Imperial and Royal Navy

Austro-Hungarian Navy kaiserliche und königliche Kriegsmarine Császári és Királyi Haditengerészet
Coat of arms of the Austro-Hungarian Navy
Active	1786–1918
Country	Austria-Hungary
Branch	Navy
Role	Defence of the Adriatic Sea
Size	4 Dreadnoughts 9 Pre-dreadnoughts 4 Coastal defence ships 3 Armoured cruisers 6 Light cruisers 30 Destroyers 36 Torpedo boats 6 Submarines
Engagements	Seven Weeks War Boxer Rebellion World War I
Commanders
Notable commanders	Wilhelm von Tegetthoff Anton Haus Maximilian Njegovan Miklós Horthy
Insignia
Naval ensign 1915–18
Naval ensign 1786–1915

The Austro-Hungarian Navy was the naval force of Austria-Hungary. Its official name in German was kaiserliche und königliche Kriegsmarine (Imperial and Royal War Navy), abbreviated as k.u.k. Kriegsmarine, and in Hungarian Császári és Királyi Haditengerészet, abbreviated as Cs. és Kir. Haditengerészet.

This navy existed under this name after the formation of the Dual Monarchy in 1867 and continued in service until the end of the First World War in November 1918. Prior to 1867, the empire's naval forces were those of the Austrian Empire. By 1915 a total of 33,735 naval personnel were serving in the k.u.k. Kriegsmarine.

After the First World War, Austria-Hungary was dismembered by the victorious western Allies and were deprived of its coast; their navy was confiscated by the Allies. Their former ports on the Adriatic Sea, such as Trieste, Pola, Fiume, and Ragusa, became parts of Italy and Yugoslavia. (After the break-up of Yugoslavia, its former coast is divided between Slovenia, Croatia, Bosnia, and Montenegro.)

Ships of the k.u.k. Kriegsmarine were designated SMS, for Seiner Majestät Schiff (His Majesty's Ship).

Until the end of the 18th century, there were only limited attempts to establish an Austrian navy. The Habsburgs had employed armed ships sailing the Danube in the 16th and 17th centuries to fight the Ottoman Empire, and ships guarding the merchant fleet also operated from the Austrian Netherlands, but these forces were neither under a common command nor did they serve a common purpose. After the Seven Years' War Austrian vulnerability to privateers in the Mediterranean Sea led Count Kaunitz to push for the creation of a small force of frigates. A specific Naval Ensign (Marineflagge) based on the red-white-red colours was introduced only in the reign of Emperor Joseph II.