Birkenstock

Last updated

Birkenstock Holding plc
FormerlyBirkenstock Group B.V. & Co. KG
Company type Public
IndustryShoe manufacturing
Founded1774;250 years ago (1774)
FounderJohann Adam Birkenstock
Headquarters,
Germany
Key people
ProductsShoes
RevenueIncrease2.svg 1.49 billion (2023)
Decrease2.svg€261 million (2023)
Decrease2.svg€75 million (2023)
Total assets Increase2.svg€4.83 billion (2023)
Total equity Increase2.svg€2.40 billion (2023)
Owner L Catterton (83%)
Number of employees
c.6,300 (2023)
Website birkenstock-group.com
Footnotes /references
[1]

Birkenstock Holding plc is a German shoe manufacturer known for its sandals and other shoes notable for contoured cork footbeds (soles), made with layers of suede and jute, which conform to the shape of their wearers' feet. Founded in 1774 by Johann Adam Birkenstock and headquartered in Neustadt (Wied), Rhineland-Palatinate, Germany, the company's original purpose was to create shoes that support and contour the foot, compared to the flat soles of many shoes during that time. In 1896 the Fussbett (footbed) was designed, and by 1925, Birkenstocks were sold all over Europe. [2]

Contents

In 1966, Margot Fraser first brought Birkenstocks to America. In the United States, they were sold in health stores, thus becoming associated with hippies in the 1970s.

History

Early years

A pair of Birkenstocks near the ocean Birkenstocks near water.jpg
A pair of Birkenstocks near the ocean

The history of the Birkenstock "shoemaking dynasty" can be traced back to the first documented mention of Johannes Birkenstock (1749–1812), registered on March 25, 1774, as a "vassal and shoemaker" in local church archives in the small Hessian village of Langen-Bergheim. [3] Since that time, there have been five generations of master shoemakers or part-time shoemakers, several lines of the Birkenstock family working in the shoemaking trade and finally three generations of shoe manufacturers. [4] In 1774, Johannes Birkenstock had already trained as a shoemaker and settled in the small Hessian town of Langen-Bergheim; he became a master shoemaker shortly afterwards. [5] After his younger brother Johann Adam Birkenstock (born 1754) died in 1790, his son Johannes (1790–1866) grew up with his uncle Johannes and also became a master shoemaker.

His grandson, Konrad Birkenstock (1873–1950), left the Wetterau after also training as a shoemaker and opened an orthopaedic shoemaker's workshop in Frankfurt am Main in 1896 and founded Konrad Birkenstock GmbH a year later. [6] Konrad Birkenstock developed the first contoured insole for use by shoemakers in the production of custom footwear. [7] [8] His success in orthopaedic circles with his insoles and health shoes and the satisfaction of his customers did not lead to financial success. The inventor Konrad Birkenstock concentrated too much on the further development of his material mix in order to further develop healthy walking. [9] When he himself was called to the orthopaedic workshop of the Friedrichsheiner Klinik in Frankfurt am Main – and therefore did not have to do military service – he relocated his business activities. In 1915, Konrad Birkenstock acquired a house in Friedberg (Hesse), where the production of insoles now took place. [10] [9] In 1925 Konrad Birkenstock acquired the Derfelt soap factory in Friedberg, Hesse, thereby expanding production. [11]

As a master orthopaedic shoemaker, Konrad Birkenstock invented a fully plastic last as early as 1897 and a fully plastic flexible insole in 1902. Shoes made on this last and with this insole were called "health footwear" by Konrad Birkenstock. [9] With this invention, Konrad Birkenstock had followed the ideas of the shoe reform, which, in keeping with the times, rethought the human body. His flexible insoles, developed along the same lines for healing purposes, differed from the rigid insoles made of metal that were common at the time. In 1914, Konrad Birkenstock's insoles were recognized as orthopaedic remedies for the first time. He gave two of these insoles the name "footbed". In 1925, Konrad Birkenstock was able to register the "Fussbett" trademark. [12] [13] [14] In the 1920s, Birkenstock insoles were already being supplied to Austria, France, Denmark, Czechoslovakia, Italy, Luxembourg, Belgium, Norway, the Netherlands, Sweden and Switzerland.

Konrad Birkenstock had three sons and one daughter. Over the course of time, they all became involved in the manufacture of orthopaedic insoles, in different companies and in different family constellations. [9] His eldest son Carl (born in 1900) followed in Konrad Birkenstock's footsteps during the First World War. He visited specialist shoe stores and shoemakers and explained to them the use and effect of the "Birkenstock system", as the combination of a fully plastic last and flexible footbed was soon called. [15] Carl continued to develop his father's deposits, was active with his own business in Vienna from 1923 to 1926 and founded Geb. Birkenstock GmbH in Steinhude am Meer together with his brothers Heinrich and Konrad Jr. in 1929. [16] From 1939, Carl Birkenstock continued to run the company, which at that time had 13 employees, alone without his brothers. [9] Carl Birkenstock took the idea of foot health even further than his father and limited sales of his insoles to specialist retailers and shoemakers who had successfully completed his training course. Although he managed to get over 6,000 people to attend this course, this approach still limited his sales options in the long term. However, it was important to him that his flexible insoles were fitted correctly in order to achieve the effect of a foot-health-preserving insole. He wanted to avoid incorrect use at all costs. [9]

Carl Birkenstock joined the National Socialist Party (NSDAP) in 1940. Carl continued to sell insoles at least until 1943. [17] There is no evidence of forced laborers in the Birkenstock family companies, which is not surprising given the small size of the companies and the non-war-related production. [9] The largest Birkenstock company - Gebr. Birkenstock GmbH in Steinhude im Meer - employed 13 people during the National Socialist era, including the owners, 6 of whom were drafted into the Wehrmacht. [9] There were no supply contracts between Birkenstock and the Wehrmacht, the Nazi Party or its organizations, though Birkenstock did attempt to gain government contracts in the early '30s, pitching his products to Hitler Youth and testing his insoles on SS members. [2] Sales during the National Socialist era were made to private individuals, often soldiers. [2] [9] [18] Birkenstock therefore did not do any business with the NSDAP, other party organizations or the Wehrmacht itself; he did not have any materials or deposits checked on the Schuhprüfstrecke of the Sachsenhausen concentration camp. Birkenstock did not profit by the company or the family "Aryanizing" Jewish property, i.e. by acquiring real estate or assets from Jewish ownership at favourable prices. Even during the National Socialist era, Carl Birkenstock was busy perfecting his idea of "natural walking". Though in 1943, he would try to enlist in the Sturmabteilung but would not be accepted. [2] Like the entire entrepreneurial family, he was not a delicate entrepreneur. This robustness led to numerous conflicts within the family, with competitors and with members of the NSDAP. [19] Birkenstock was neither an ideologically convinced National Socialist nor a hero. Even though he wanted to do something good for mankind with his healthy footwear, his dealings with individuals were robust. [20] [9]

After World War II (1939–1945), the Birkenstock sandal was popular among returning soldiers because of the orthopedic support. [21] After 1945, Carl Birkenstock continued to pursue his idea of his handmade healthy footwear at his new headquarters in Bad Honnef near Bonn. He wanted to make this "ideal shoe" suitable for mass production, which he tried to realize together with shoe manufacturers until 1961, when he abandoned this idea and retired to writing books on foot health. [20] During this time, the still very small company earned money through the successful sale of the "Blue Footbed" orthopaedic insole. In 1954, Carl's only son, Karl, joined his father's company. While his grandfather Konrad and father Carl Birkenstock worked all their lives on producing orthopaedic insoles that were as individualized as possible for the wearer, the young Karl Birkenstock succeeded in making healthy footwear mass-produced in 1962 with the invention of a standardized, permanently installed, anatomically shaped insole. [20] [22]

In 1963, Karl Birkenstock released his first model, the "Original Birkenstock Footbed Sandal", an athletic sandal with a flexible footbed, which has been called "Madrid" since 1979, laying the foundation for the company's expansion since the 1970s. The shoe was constructed so that the wearer would have to grip their toes to keep the sandals on; this resulted in toning the calf muscle, [23] which became quite useful to athletes, especially among gymnasts. [24] [ better source needed ] However, the market launch in 1963 was a disaster. No shoe retailer wanted to offer the gender-neutral sandal, which was diametrically opposed to the shoe fashion trend of the time - Italian stilletos - and consequently orders failed to materialize. The first sales were made through direct marketing in the medical sector. Birkenstock Orthopädie GmbH, as the company was now called, was run jointly by Karl and his wife Gisela. [25] The number of employees in 1970 was 57. [20]

Margot Fraser and introduction to U.S.

A Birkenstock branded store, Birkenstock Village, in Santa Rosa, California Birkenstock Village - April 2022 - Sarah Stierch 01.jpg
A Birkenstock branded store, Birkenstock Village, in Santa Rosa, California

In 1966, Margot Fraser, a German-American dressmaker who resided in Santa Cruz, California, decided to travel back to Germany to visit a spa in Bavaria, where she was recommended Madrids to help with a foot ailment caused by tight shoes. [23] [26] [27] Due to Fraser's relief from her foot condition and her enthusiasm for the sandals, Birkenstocks were introduced in the United States—though some hurdles stood in the way of their eventual acceptance by American buyers. Many shoe stores rejected the sandals due to their appearance, leading Fraser to health stores near the granola section. [28] The 1970s brought a spike in sales. In the United States, Birkenstocks were first popular among young men and later on among flower children, a group traditionally associated with American liberalism. The shoe became popular with hippies and others who had a "back to nature" philosophy and appreciated the natural foot shape and foot-friendly comfort of Birkenstocks. [29] Hippies and representatives of the tech movement in California discovered the shoes as an expression of the unconventional. [30] [31] [32] In the 1970s, Fraser successfully continued to sell them from organic supermarkets and quickly expanded with her company, Birkenstock Footprint Sandals, Inc., in Novato, California, which later became Birkenstock USA, in the largest market for Birkenstocks since the 1980s. [33]

Birkenstock sandals became popular in Germany in the 1980s. Since the 1960s, Birkenstock sandals had become popular in the care professions and in the alternative and peace movement, and then also in "middle-class" households as slippers and leisure shoes. They were not developed for the medical sector, but were designed from the outset for young and old as well as all types of occupations and leisure activities. [34] Although derided at the shoe trade fair in 1963, Karl Birkenstock developed the closed sandal "Zürich" the following year, followed by the strappy sandal "Roma" in 1965, the low shoe "Oslo" and the boot "Athen" in the second half of the 1960s. [35] [36] A first plastic model - the "Noppy" massage sandal - saw the light of day in the new decade. In 1973, Birkenstock's most popular sandal, Arizona, was introduced. [37] This was followed in 1976 by the first cork clog, the "Boston", and finally in 1983 by the range of thong sandals, including the "Gizeh".

Expansion and present-day

Fraser's trading company named Birkenstock Footprint Sandals, Inc., was renamed Birkenstock Distribution USA, Inc. (BDUSA) in 2005. The company remained until 2007 the exclusive importer and distributor of Birkenstock name-brand products in the United States. In 2007 the owners of Birkenstock Orthopädie GmbH & Co. KG purchased their long-standing distribution partner BDUSA. [38] [ better source needed ]

In 1986 Nordstrom became the first department store to sell Birkenstock sandals.

The success of Birkenstock sandals on the European markets and in the USA since the 1970s led to strong growth for the company. After German reunification in 1990, Karl Birkenstock seized the opportunity and expanded production into the new federal states. [39] However, growth came at a price: conflicts arose with various trade unions in the company. After Karl Birkenstock retired from the company in the early 2000s, his three sons, Christian, Stephan, and Alexander Birkenstock, took over management and ownership. The handover took the form of a multi-brand strategy, with Alexander, Christian and Stephan Birkenstock each responsible for their own brands and companies. [39] Each of them had different ideas for the company's future and ended up creating multiple competing product lines and subsidiaries.

Since the 1980s, the fashion world, celebrities and designers have discovered Birkenstock for themselves and sent models down the catwalk in the sandals. The first appearance with André Walker in New York can be traced back to 1983. [40] Pictures of models also adorned covers and articles in well-known fashion magazines. [30] As a result, the sandals also became increasingly popular in the so-called mainstream, until the multi-brand strategy gradually eroded customer interest. Serious disputes developed, particularly with the US market and Margot Fraser, over the new competing brands within the Birkenstock Group.

Birkenstock EVA Gizeh GIZEH - Cuir Exquisite - Noir.jpg
Birkenstock EVA Gizeh

In the early 1990s, "Birks" enjoyed another spike in sales among high-school and college-aged Generation Xers, in part due to the introduction of Birkenstocks into High Fashion, most notably, Kate Moss. Birkenstocks continued to spread to Britain in the early 2000s due to headlines of Gwyneth Paltrow, who was spotted wearing them. [41] Birkenstocks saw another comeback among teens and young adults in the early 2010s, as well as in the late 2010s due in part to the VSCO girl trend. [42] The company was given PETA's Libby Award for being the "Most Animal-Friendly Shoe Company" in 2018. [43]

In 2013, the company, which had previously consisted of 38 individual companies since the 1990s, was fundamentally restructured to form a single group of companies, the Birkenstock Group. In 2013, Stephan sold his stake to the two brothers; they recruited Oliver Reichert, an outsider, to consolidate various subsidiaries into Birkenstock Group and lead the company. [23] [44] [45]

In February 2021, the American-French investment company L Catterton and the family holding Financière Agache, the private equity firm backed by Bernard Arnault's LVMH, acquired a majority stake in the German sandal manufacturer Birkenstock. The parties have agreed not to disclose the purchase price or other details of the transaction. According to media reports, they had agreed to buy Birkenstock in a deal that valued the company at about €4bn. [46] Christian and Alex Birkenstock retained minority ownership and remained responsible for production in Germany. [47]

In September 2023, Birkenstock filed for an initial public offering (IPO) in the United States stating that the company would be listed on the New York Stock Exchange under the stock ticker "BIRK". [48] [49] The company completed the IPO and went public on 11 October 2023 raising US$1.48 billion valuing the company at $8.64 billion. Following the IPO, L Catterton continued to be a controlling shareholder with 83 percent ownership. [50] Alex exited his stake following the IPO. [51]

As of 2023, 72 percent of their customers were female. [52]

High fashion

Birkenstock has been collaborating with fashion brands and designers since the early 2000s. The third collaboration - initially the most significant due to its duration - was with Heidi Klum from 2003. In 2012 Birkenstocks were spotted on a Céline runway in Paris. Called "Furkenstocks", this recreation of the Arizona sandal incorporated a mink-covered footbed. The "Furkenstocks" caused a sensation and soon original Birkenstock sandals were appearing in fashion magazines again. [53] [54] Besides Céline's creative director Phoebe Philo, many other designers have also created their version of the sandal, including Giambattista Valli and Givenchy. [23]

In 2019 Valentino collaborated with Birkenstock to create their version of the sandal featured at Men's Paris Fashion Week. [55]

On June 3, 2021, the Birkenstock Group announced a collaboration with fashion designer Rick Owens. [56] Starting on June 4 of that year, interpretations of the Arizona and Boston models were released. A new Rotterdam style was also presented and released for sale.[ citation needed ]

Production

A pair of black Arizona ESD Birkenstocks Birkenstock Arizona ESD.jpg
A pair of black Arizona ESD Birkenstocks

The original footbed of the Birkenstock shoe was created in the 1930s and possesses four different layers that complete the shoe. The first layer of the shoe is the shock-absorbent sole, followed by a layer of jute fibers, a firm cork footbed, and another layer of jute. The last layer is the footbed line which is a soft suede. [57] [ better source needed ]

In addition to the original footbed, Birkenstock gives the option of a soft footbed. The shoe is made of the same materials as the original footbed, with the addition of a foam insert placed under the suede lining. [58]

In 2015, Birkenstock introduced a lightweight, waterproof shoe called the Birkenstock EVA, made of a material called ethylene-vinyl acetate (EVA). [59] [60]

Related Research Articles

<span class="mw-page-title-main">Shoe</span> Footwear

A shoe is an item of footwear intended to protect and comfort the human foot. Though the human foot can adapt to varied terrains and climate conditions, it is vulnerable, and shoes provide protection. Form was originally tied to function, but over time, shoes also became fashion items. Some shoes are worn as safety equipment, such as steel-toe boots, which are required footwear at industrial worksites.

<span class="mw-page-title-main">Footwear</span> Garments worn on feet

Footwear refers to garments worn on the feet, which typically serve the purpose of protection against adversities of the environment such as wear from rough ground; stability on slippery ground; and temperature.

<span class="mw-page-title-main">Adidas</span> German multinational clothing and apparel corporation

Adidas AG is a German athletic apparel and footwear corporation headquartered in Herzogenaurach, Bavaria, Germany. It is the largest sportswear manufacturer in Europe, and the second largest in the world, after Nike. It is the holding company for the Adidas Group, which also owns an 8.33% stake of the football club Bayern München, and Runtastic, an Austrian fitness technology company. Adidas's revenue for 2018 was listed at €21.915 billion.

<span class="mw-page-title-main">Dr. Martens</span> Footwear brand

Dr. Martens also known as Doc Martens, Docs, or DMs, is a footwear and clothing brand, headquartered in Wollaston, Northamptonshire. Although famous for its footwear, the company also makes a range of accessories including clothing and bags. The footwear is distinguished by its air-cushioned sole, upper shape, welted construction, and yellow stitching. The Dr. Martens' design studio is in Camden Town, London, England. The company manufactures in the UK, China, Vietnam, Laos, and Thailand. The company is listed on the London Stock Exchange and is a constituent of the FTSE 250 Index.

<span class="mw-page-title-main">Sandal</span> Type of footwear with an open upper

Sandals are an open type of shoe, consisting of a sole held to the wearer's foot by straps going over the instep and around the ankle. Sandals can also have a heel. While the distinction between sandals and other types of footwear can sometimes be blurry, the common understanding is that a sandal leaves all or most of the foot exposed. People may choose to wear sandals for several reasons, among them comfort in warm weather, economy, and as a fashion choice. Usually, people wear sandals in warmer climates or during warmer parts of the year in order to keep their feet cool and dry. The risk of developing athlete's foot is lower than with enclosed shoes, and the wearing of sandals may be part of the treatment regimen for such an infection.

<span class="mw-page-title-main">Shoemaking</span> Process of making footwear

Shoemaking is the process of making footwear.

<span class="mw-page-title-main">Slide (footwear)</span> Open-toed slip-on sandal shoe

Slides or sliders are a type of light shoe that is characterized by having a loose heel that holds on to the foot from the front. Like flip-flops, they are typically employed in casual situations, in addition to being unisex footwear worn by both sexes. Sliders are distinguished from flip-flops by their vamp strap which does not separate the big toe from the rest of the toes.

<span class="mw-page-title-main">Sergio Rossi</span> Italian shoe designer company

Sergio Rossi is an Italian fashion brand that focuses on footwear. The company was founded in 1951 by Sergio Rossi.

Kaufman Footwear was a Kitchener, Ontario-based shoe company. It was known for its Sorel brand.

<span class="mw-page-title-main">Deckers Brands</span> Consumer retail company

Deckers Outdoor Corporation, doing business as Deckers Brands, is a footwear designer and distributor based in Goleta, California, United States. It was founded in 1973 by University of California, Santa Barbara alumni Doug Otto and Karl F. Lopker. In 1975, the company was incorporated in California under the name Deckers Corporation. In October 1993, Deckers initiated a public offering of stock in its company. Deckers' portfolio of brands includes UGG, Teva, Hoka One One, and Koolaburra.

<span class="mw-page-title-main">Naot</span> Israeli footwear company

Teva Naot is an Israeli shoe and sandal manufacturer based at Kibbutz Neot Mordechai.

Crocs, Inc. is an American footwear company based in Broomfield, Colorado, that manufactures and markets the Crocs brand of foam footwear. Crocs, Inc. term these "clogs", but they do not contain any wood like traditional clogs.

Alpina is a Slovenian footwear manufacturing company founded in 1947 after several private shoe making workshops with long tradition merged in the town of Žiri. Initially named "Žiri Shoe Factory", it was renamed "Alpina" in 1951. In 1985, the company employed almost 2,000 people. Alpina operates as a joint stock company, with approximately a thousand employees producing over 1.7 million pairs of shoes and boots each year. The greater part of production is sold abroad under their own brand name.

<span class="mw-page-title-main">Salvatore Ferragamo S.p.A.</span> Italian luxury fashion company

Salvatore Ferragamo S.p.A., doing business as Ferragamo, is an Italian luxury fashion house focused on apparel, footwear, and accessories headquartered in Florence, Italy. It specializes in designing and manufacturing footwear and leather goods, which together account for over 86% of its revenue. The remaining products include ready-to-wear, silk products, fashion accessories, and licensed eyewear, watches, and perfumes. It operates 447 mono-brand stores worldwide as of September 2022.

Bernardo Sandals was founded in 1946 by architect Bernard Rudofsky and Berta Rudofsky. The Rudofskys went into sandal design following the 1944 exhibition, "Are Clothes Modern?" that Mr. Rudofsky curated at the Museum of Modern Art in New York City.

Prestel Publishing is an art book publisher, with books on art, architecture, photography, design, fashion, craft, culture, history and ethnography. Lists range from museum guides, to encyclopaedias, art and architecture monographs to facsimile volumes and books for children.

Sergio Rossi was an Italian shoe designer, who founded his own brand.

<span class="mw-page-title-main">Allbirds</span> Footwear company

Allbirds, Inc. is a New Zealand and American public benefit company that sells footwear and apparel, co-founded in 2014 by Tim Brown and Joey Zwillinger. The company is headquartered in San Francisco, California. Its business model has historically relied on direct-to-consumer commerce, though it has some brick and mortar commerce.

R.G. Barry Corporation, stylized RG Barry, is a developer and marketer of footwear, handbags, and foot care products. It was founded by Florence Melton, Aaron Zacks, and Harry Streim in 1947 in Columbus, Ohio. Headquartered in Pickerington, Ohio, RGB is a consumer-driven, multi-channel, digitally-led brand management platform developed to accelerate growth and innovation for lifestyle consumer brands. More commonly known for their lifestyle brands, Bagggallini and Dearfoams which focus on functional handbags and cozy slippers. While changing the standards for comfort, RGB also focuses on becoming an earth-first brand through their biodegradable brand Planet A, and innovations such as REGNR8.

<span class="mw-page-title-main">On (company)</span> Swiss athletic shoe and performance sportswear company

On Holding AG is an athletic shoe and performance sportswear company originating in Switzerland that designs and markets sports clothing and running shoes.

References

  1. "Birkenstock Holding plc 2023 Annual Report (Form 20-F)". US Securities and Exchange Commission. 18 January 2024.
  2. 1 2 3 4 Loh, Tim. "How Birkenstock Became an Improbable Luxury Empire". Bloomberg.com. Archived from the original on 5 June 2024. Retrieved 24 July 2024.
  3. Baptismal certificate of Johann Peter Ditzel's son dated March 25th 1774, in: Hessen-Nassau: Zentralarchiv der Evang. Kirche, Büdingen deanery, Eckartshausen parish, baptism register 1757-1799, marriage register 1757-1799, viewed online at www.archion.de [last access 6. 9. 2022], image 127.
  4. Kai Balasz-Bartesch/Andrea H. Schneider-Braunberger, The Shoemaker Family Birkenstock, in: Andrea Schneider-Braunberger (ed.), Birkenstock. The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024, ISBN   978-3-7913-9332-2, pp. 36–55.
  5. Baptismal certificate of Johann Adam Birkenstock 1781, in: Hessen-Nassau: Central Archive of the Protestant Church, Büdingen Deanery, Eckartshausen Parish, Baptism Register 1757-1799, marriage register 1757-1799, viewed online at www.archion.de [last access 6. 9. 2022], picture 206.
  6. Institute for City History, (Institut für Stadtgeschichte) Frankfurt am Main
  7. Odriozola, Amaia (6 October 2023). "Birkenstock goes public: This is how the 'woke' sandal became a fashion symbol". El Pais.
  8. "How Birkenstock went from 'ugly' sandal to trendy fashion staple: the popular German LVMH-owned footwear brand elevated its status with Barbie, Kendall Jenner and collaborations with Valentino". South China Morning Post. 11 August 2023.
  9. 1 2 3 4 5 6 7 8 9 10 Roman Köster, Misjudged Innovations: The Struggle for Foot Orthopedics, 1896-1945, in: Andrea H. Schneider-Braunberger (ed.), Birkenstock. The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024; ISBN   978-3-7913-9332-2, pp. 62-98.
  10. City Archive Friedberg
  11. Axel Arbinger, Nobody walks on metal soles anymore. The history of the Birkenstock company - laying the foundations for a global reputation in the "Indian Quarter", in: Friedberg-Magazin (April 1995), in: City Archive Friedberg.
  12. German Reich Patent Office, No. 343209, entry dated 11. 11. 1925.
  13. Jennings, Helen (14 August 2020). "The secret of Birkenstock's enduring success". CNN Style.
  14. "History: Birkenstock Group". www.birkenstock-group.com. Retrieved 25 April 2017.
  15. City Archive Friedberg
  16. Niedersächsisches Landesarchiv, Abt. Bückeburg [henceforth NLA BU], Gewerbekartei, L 121b, Acc 2001, 025, no. 197. Acc 2001, 025, no. 197.
  17. CA Birkenstock, BS 10, turnover Carl Birkenstock Steinhude.
  18. CA Birkenstock, BS 54, Statement by Carl Birkenstock to my old followers in Presence of the trade union leader Mr. Otto Jahr, 2. 5. 1946.
  19. City Archive Friedberg
  20. 1 2 3 4 Jörg Lesczenski, On the Path to “Walking as Intended by Nature”: From the Footbed to a Shoe, in: Andrea H. Schneider-Braunberger (ed.), Birkenstock. The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024, ISBN   978-3-7913-9332-2, pp. 120–168.
  21. e.V., Deutsche Zentrale für Tourismus. "Johan Adam Birkenstock". www.germany.travel. Retrieved 25 April 2017.
  22. Andrea H. Schneider-Braunberger, The System Birkenstock: The Footprint for Walking as Nature Intended, in: Andrea H. Schneider-Braunberger (ed.), Birkenstock. The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024, ISBN   978-3-7913-9332-2, pp. 104-118.
  23. 1 2 3 4 Mead, Rebecca (16 March 2015). "Sole Cycle". The New Yorker.
  24. "Walking History – the one-strap Madrid sandal". Birkenstock Group. Retrieved 16 November 2020.
  25. Alexander von den Benken, From Family Business to Global Corporation, in: Andrea H. Schneider-Braunberger (ed.), Birkenstock. The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024, ISBN   978-3-7913-9332-2, p. 175.
  26. Groves, Martha (20 February 1990). "Footwear's Ugly Duckling Grows Up : Fashion: Clunky Birkenstock sandals were part of the 1960s counterculture. Now their U.S. distributor hopes some stylish updating will broaden their market appeal in the 1990s". Los Angeles Times.
  27. "Talk with founder and former CEO of Birkenstock, Margot Fraser". 7 April 2010. Archived from the original on 26 April 2017. Retrieved 25 April 2017.
  28. Horyn, Cathy (20 August 2018). "Cathy Horyn Travels to Germany to Understand the Unlikely Return of Birkenstocks". The Cut. Retrieved 16 November 2020.
  29. Carr, Collie (12 March 2006). "Thank You for Insulting Our Sandals". The New York Times . Accessed 7 May 2012.
  30. 1 2 Alice Janssen, International Fashion and Luxury in Birkenstocks, in: Andrea H. Schneider-Braunberger (ed.), Birkenstock, The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024, ISBN   978-3-7913-9332-2, pp. 246–284.
  31. Emily Brayshaw, Birkenstock in Australia, in: ibid, pp. 355–366.
  32. Taylor Bridges, Form Hippie to High Fashion: The Evolution of Birkenstock in North America, in: ibid., pp. 304–313.
  33. Alexander von den Benken, From Family Business to Global Corporation, in: Andrea H. Schneider-Braunberger (ed.), Birkenstock. The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024, ISBN 978-3-7913-9332-2, p. 179.
  34. Christian Kleinschmidt/Andrea H. Schneider-Braunberger, Birkenstock: A Purpose Brand, in: Andrea H. Schneider-Braunberger (ed.), Birkenstock. The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024, ISBN   978-3-7913-9332-2, pp. 218–232.
  35. Schuhwirtschaft No. 17 of 25.4.1963 and Fachkunde of 19.3.1963.
  36. Andrea H. Schneider-Braunberger, The Names of the Original Birkenstock-Footbed Sandals, in: Andrea H. Schneider-Braunberger (ed.), Birkenstock. The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024, ISBN   978-3-7913-9332-2, pp. 169–173.
  37. Cary, Alice (3 June 2023). "How Birkenstock's Arizonas Went From Being Sold Exclusively In Health-Food Stores To A Fashion Editor Staple". British Vogue.
  38. "History: Birkenstock Group". www.birkenstock-group.com. Retrieved 16 November 2020.
  39. 1 2 Alexander von den Benken, From Family Business to Global Corporation, in: Andrea H. Schneider-Braunberger (ed.), Birkenstock. The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024, ISBN   978-3-7913-9332-2, pp. 174–217.
  40. Illustration from André Walker in New York (photo by Amy Arbus), in: Andrea H. Schneider-Braunberger (ed.), Birkenstock. The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024, ISBN   978-3-7913-9332-2, p. 257.
  41. Helen Jennings. "The secret of Birkenstock's enduring success". CNN. Retrieved 16 November 2020.
  42. Wu, Jasmine (9 September 2019). "Teen culture shifted to embrace brands, and the VSCO girl was born". CNBC. Retrieved 28 October 2020.
  43. Barbara Schneider-Levy,"Birkenstock Is Voted Most Animal-Friendly Shoe Company by PETA’s Youth Group," FootwearNews.com, 14 February 2018.
  44. Debter, Lauren (2 March 2021). "Birkenstock Billionaires Unveiled After German Sandal Maker Agrees To Sell In A $4.7 Billion Deal". Forbes.
  45. Paton, Elizabeth (11 October 2023). "From LSD to I.P.O." The New York Times.
  46. Zlaty, Hanna (26 February 2021). "Birkenstock sold to group backed by Europe's richest man". CNN Business.
  47. Butler, Sarah (26 February 2021). "German sandal maker Birkenstock taken over by LVMH-backed group". The Guardian.
  48. Pequeño IV, Antonio (12 September 2023). "Birkenstock Files For IPO Two Years After Its $4.3 Billion Acquisition". Forbes.
  49. Saini, Manya; Nishant, Niket; Saini, Manya; Nishant, Niket (2 October 2023). "Germany's Birkenstock targets $9.2 billion valuation in New York IPO". Reuters. Retrieved 2 October 2023.
  50. Gould, Ryan; Hytha, Michael (10 October 2023). "Birkenstock Prices IPO Within Range at $46 a Share". Bloomberg News.
  51. Stupples, Ben; Maloney, Tom (11 October 2023). "Birkenstock heirs are now worth $3.4 billion after the 250-year-old shoemaker's high-profile IPO". Fortune.
  52. Wood, Zoe (9 October 2023). "From frumpy sandal chic to mainstream appeal: will Birkenstock IPO be a perfect fit?". The Guardian.
  53. Alice Janssens, International Fashion and Luxury in Birkenstocks, in: Andrea H. Schneider-Braunberger (ed.), Birkenstock, The Evolution of a Universal Purpose and Zeitgeist Brand, (Prestel) Munich, London, New York 2024, ISBN   978-3-7913-9332-2, p. 282.
  54. Nnadi, Chioma. "Pretty Ugly: Why Vogue Girls Have Fallen for the Birkenstock". Vogue.com.
  55. Klerk, Amy de (17 January 2019). "Valentino has given Birkenstocks a high-fashion spin". Harper's BAZAAR. Retrieved 18 November 2020.
  56. "Birkenstock and Rick Owens Continue Their Partnership for a Third Season" (Press release). Birkenstock Group. Retrieved 29 July 2021.
  57. "Our Footbed". www.birkenstock.com. Retrieved 7 May 2017.
  58. "A fascinating insight into the soft footbed by Birkenstock". Daily News and Analysis. 7 February 2022.
  59. Dawkins, Jennifer Ortakales (4 October 2023). "The rise of Birkenstock: How the shoe brand turned an ugly hippie sandal into coveted fashion statement and has now filed for an IPO". Business Insider.
  60. "BIRKENSTOCK Footwear: Birkenstock Group". www.birkenstock-group.com. Retrieved 13 November 2020.