The Orzeł class was a short series of submarines built in Dutch shipyards for the Polish Navy in the 1930s. Four submarines were planned but only two were completed. They saw service during World War II.
Pietro Micca was an Italian submarine which served with the Regia Marina in World War II. She was the third ship named after Pietro Micca, the Savoyard soldier who became a national hero for his sacrifice in the defence of Turin against the French troops in 1706. This boat was the prototype for a class of fast, long range submarines with conventional torpedo armament, naval mine laying capability, and useful secret transport capacity. The ship was built at the Tosi shipyard in Taranto. She was laid down on 15 October 1931 and launched on 31 March 1935. The boat fully met design requirements, but was too expensive to be repeated.
Sava was a Flutto-class submarine in service with the Yugoslav Navy. Built by Cantieri Riuniti dell'Adriatico in Monfalcone during the Second World War, Sava was laid down and completed as Nautilo for service with the Italian Regia Marina.
NMS Marsuinul was a submarine of the Romanian Navy, one of the few warships built in Romania during the Second World War. She was the largest Romanian-built submarine and the most powerful and modern Axis submarine in the Black Sea.
During the Second World War, the Royal Romanian Navy operated a total of 9 submarines: three fleet submarines and six midget submarines. These vessels fought on the Axis side during the war. Only two of them survived the war and continued to serve in the Romanian Navy until the 1960s.
O'Byrne was a submarine of the French Navy, the lead ship of her class. She was ordered by Romania during World War I and laid down in April 1917 at the Schneider Shipyard in Gironde. However, she was requisitioned by French authorities at the end of the year and completed for the French Naval Forces. Upon commissioning in 1921, she became the first French submarine to be completed between 1919 and 1944.
The Requin-class submarines were a class of nine diesel-electric attack submarines built for the French Navy in the mid-1920s. Most saw action during World War II for the Vichy French Navy or the Free French Naval Forces. Nine ships of this type were built in the shipyards of Brest, Cherbourg and Toulon between 1923 and 1928. The class was part of the French Marine Nationale, serving in the Mediterranean Sea. All member ships took part in World War II, fighting on both sides of the conflict; Four were captured by Italian forces and sunk by the Allies. Only one ship survived the war - Marsouin, decommissioned shortly after the war's end.
The French submarine Saphir was the lead ship of the Saphir-class submarines built for the French Navy in the mid-1930s. Laid down in May 1926, it was launched in December 1928 and commissioned in September 1930. Saphir was disarmed at Bizerte, Tunisia and renamed FR 112 after being captured there by Italian forces on 8 December 1942. Saphir was seized and scuttled by German forces at Naples, Italy on 15 September 1943.
The O'Byrne-class submarines were a class of three submarines built for the French Navy from 1917 to 1921. They were originally ordered by the Romanian Navy, but were confiscated by the French government while still under construction. Three ships of the type were built between 1917 and 1921 at the Schneider shipyard in Chalon-sur-Saône. They were commissioned in the French Navy, serving in the Mediterranean Sea. The ships were removed from the Navy list between 1928 and 1935. The first ship of its class was named in honour of French submariner Gabriel O'Byrne.
The French submarine Louis Dupetit-Thouars was the last of three submarines built for the French Navy from 1917 to 1920. It were originally ordered by the Romanian Navy, but was confiscated by the French government during World War I while still under construction. It was built at the Schneider shipyard in Chalon-sur-Saône. Louis Dupetit-Thouars was commissioned in the French Navy, serving in the Mediterranean Sea. The ship was stricken from the Navy list and sold for scrap in 1928.
The Lagrange-class submarines were a class of four submarines built for the French Navy during World War I and the interwar period. Three ships of this type were built in the Arsenal de Toulon from 1913 to 1924, and one was built at the Arsenal de Rochefort shipyard. Entering the French Marine Nationale from 1918 to 1924, the submarines served until the mid-1930s.
The French submarine Lagrange (Q112) was a Lagrange-class submarine built for the French Navy built between 1913 and 1918. It was laid down in the Arsenal de Toulon shipyards and launched on August 12, 1919. Lagrange was completed in 1918 but saw no action during World War I and served in the French Marine Nationale until 1935.
The French submarine Regnault (Q113) was a Lagrange-class submarine built for the French Navy built between 1913 and 1924. It was laid down in the Arsenal de Toulon shipyards and launched on June 25, 1924. Regnault was completed in 1924 and served in the French Marine Nationale until 1937.
The Joessel-class submarines were a class of two diesel-electric submarines built for the French Navy laid down before the start of World War I and completed after. They were built in the Arsenal de Cherbourg from 1913 to 1920, before entering the French Marine Nationale in 1920 and serving until 1936.
The French submarine Joessel was a Joessel-class diesel-electric attack submarine built for the French Navy between 1913 and 1919. Joessel was built in the Arsenal de Cherbourg from 1913 to 1917, entered the French Marine Nationale in February 1920 and served until 1936.
The Armide-class submarines were a class of three diesel-electric submarines built for the Greek and Japanese Navies before and during World War I. They were built in the Schneider-Creusot shipyards 1913 to 1918, but were seized during the war by the French government before they could be sold. The Armide class ships operated in the Mediterranean during the course of World War I and were stricken from the Navy list between 1928 and 1935.
Armide was a submarine ordered by the Japanese Navy from the Schneider-Creusot shipyard before World War I but was requisitioned by the French government before it was launched. Armide operated in the Mediterranean during the course of World War I and was stricken from the Navy list in July 1932.
The French submarine Amazone was an Armide-class diesel-electric attack submarine built for the Greek Navy before and during World War I. It was built in the Schneider-Creusot shipyards between 1913 and 1916, but was seized during the war by the French Government before it could be sold, on 3 June 1915. Amazone operated in the Adriatic Sea during the course of World War I and was stricken from the Navy list in July 1932.
The French submarine Antigone was an Armide-class diesel-electric attack submarine originally ordered by Greece. It was built in the Schneider-Creusot shipyards between 1912 and 1917, but was requisitioned on 30 May 1917 by the French Government before it was delivered. Antigone operated in the Mediterranean during the course of World War I and was stricken from the Navy list in August 1935.
Romania 
France