|Luxembourgish National Holiday|
|Official name||Lëtzebuerger Nationalfeierdag|
|Next time||23 June 2023|
|Related to||Monarchy of Luxembourg|
The Grand Duke's Official Birthday (Luxembourgish: Groussherzogsgebuertsdag, French : Célébration publique de l'anniversaire du souverain), also known as Luxembourgish National Day (Luxembourgish : Lëtzebuerger Nationalfeierdag, French : Fête nationale luxembourgeoise, German : Luxemburgischer Nationalfeiertag),  is celebrated as the annual national holiday of Luxembourg. It is celebrated on 23 June, although this has never been the actual birthday of any ruler of Luxembourg. When the monarch of Luxembourg is female, it is known as the Grand Duchess's Official Birthday.
The monarch's birthday has not always been celebrated on 23 June. Under William I (1815–1840), the date was 24 April (although his actual birthday was 24 August), and under William II (1840–1849), it was 6 December, his actual birthday. Because William I abdicated between 24 April and 6 December, the holiday was celebrated twice in 1840.  Under William III (1849–1890), the date was set at 17 June until 1859, after which his birthday was celebrated on 19 February, two days after his actual birthday. 
With the separation of the orders of succession, the Dutch and Luxembourgish thrones split in 1890. The Nassau-Weilburg monarchs celebrated their official birthdays on their actual birthdays. In 1947, the day was declared the 'national holiday'.  As both the then-reigning Charlotte and the heir apparent (and regent) Jean were born in January, it was feared that their actual birthdays, therefore the nation's holiday, would be marred by poor weather.  Thus, on 23 December 1961, the date was fixed on 23 June by Grand Ducal decree. 
Saint-Jean-Baptiste Day, also known in English as St John the Baptist Day, is a holiday celebrated on June 24 in the Canadian province of Quebec and by French Canadians across Canada. It was brought to Canada by French settlers celebrating the traditional feast day of the Nativity of Saint John the Baptist. It was declared a public holiday in Quebec in 1925, with publicly financed events organized province-wide by a Comité organisateur de la fête nationale du Québec.
"Ons Heemecht" is the national anthem of Luxembourg. Written by Michel Lentz in 1859 and set to music by Jean Antoine Zinnen in 1864, it is performed at national celebrations, while the royal anthem, or, more accurately, the grand ducal anthem, "De Wilhelmus", is performed at entrances or exits of members of the Grand Ducal Family.
The grand duke of Luxembourg is the monarchical head of state of Luxembourg. Luxembourg has been a grand duchy since 15 March 1815, when it was created from territory of the former Duchy of Luxembourg. It was in personal union with the United Kingdom of the Netherlands until 1890 under the House of Orange-Nassau. Luxembourg is the world's only sovereign Grand Duchy and since 1815, there have been nine monarchs, including the incumbent, Henri.
Victoria Day is a federal Canadian public holiday celebrated on the last Monday preceding May 25 to honour Queen Victoria. The holiday has been observed in Canada since at least 1845, originally on Victoria's natural birthday, May 24. It falls on the Monday between the 18th and the 24th (inclusive) and, so, is always the penultimate Monday of May. Victoria Day is a federal statutory holiday, as well as a holiday in six of Canada's 10 provinces and all three of its territories. The holiday has always been a distinctly Canadian observance and continues to be celebrated across the country, being informally considered the start of the summer season in Canada.
Jean was the Grand Duke of Luxembourg from 1964 until his abdication in 2000. He was the first Grand Duke of Luxembourg of French agnatic descent.
Marie-Adélaïde, reigned as Grand Duchess of Luxembourg from 1912 until her abdication in 1919. She was the first Grand Duchess regnant of Luxembourg, its first female monarch since Duchess Maria Theresa and the first Luxembourgish monarch to be born within the territory since Count John the Blind (1296–1346).
Prince Guillaume, Hereditary Grand Duke of Luxembourg, is the heir apparent to the crown of Luxembourg since his father's accession in 2000.
The King's Official Birthday is the selected day in most Commonwealth realms on which the birthday of the monarch is officially celebrated in those countries. It does not necessarily correspond to the date of the monarch's actual birth.
The Chamber of Deputies, abbreviated to the Chamber, is the unicameral national legislature of Luxembourg. Krautmaart is sometimes used as a metonym for the Chamber, after the square on which the Hôtel de la Chambre is located.
The Grünewald is a forest in central Luxembourg, most of which is owned by the national government. Grünewald stretches through the communes of Niederanven, Steinsel, and Walferdange; the centre of the forest is situated 6 kilometres (3.7 mi) north-east of central Luxembourg City. As a result of its proximity to Luxembourg's capital city, it is a popular destination for tourism, leisure, and hospitality. Within the Grünewald are the sources of the Black Ernz and the White Ernz.
Berg Castle, also called Colmar-Berg, is the principal residence of the Grand Duke of Luxembourg. It is situated in the town of Colmar-Berg, in central Luxembourg, near the confluence of the Alzette and the Attert, two of Luxembourg's most important rivers.
There are a number of national symbols of Luxembourg, representing Luxembourg or its people in either official or unofficial capacities.
The Hôtel de la Chambre des Députés is the meeting place of the Luxembourgish national legislature, the Chamber of Deputies, in Luxembourg City, in southern Luxembourg.
The Grand Ducal Gendarmerie was the national Gendarmerie force of the Grand Duchy of Luxembourg, carrying both civil and military duties. It merged on January 1, 2000, with local police forces under state authority to form the Grand Ducal Police, the country's current national police force.
This is a list of public holidays in Luxembourg.
"De Wilhelmus" is the grand ducal anthem of Luxembourg. Lyrics for it were written in 1919 by Luxembourgish writer Nik Welter, although they are not often used in official performances. The anthem is performed whenever a member of the Grand Ducal Family enters or leaves an official ceremony, while the national anthem, "Ons Heemecht", is performed at national celebrations.
The Constituent Assembly of Luxembourg was a constituent assembly called in 1848 in Luxembourg to write and pass a new national constitution.
The German invasion of Luxembourg was part of Case Yellow, the German invasion of the Low Countries—Belgium, Luxembourg and the Netherlands—and France during World War II. The battle began on 10 May 1940 and lasted just one day. Facing only light resistance, German troops quickly occupied Luxembourg. The Luxembourgish government, and Grand Duchess Charlotte, managed to escape the country and a government-in-exile was created in London.
The fête nationale is a holiday in many places, frequently as a public holiday. It is a French language term for National Holiday, so is used in places that use French.