Kiel Fjord and Kiel as a village was probably first settled by Vikings who wanted to colonise the land which they had raided, and for many years they settled in German villages. This is evidenced by the geography and architecture of the fjord. The city of Kiel was founded in 1233 as Holstenstadt tom Kyle by Count Adolf IV of Holstein, and granted Lübeck city rights in 1242 by Adolf's eldest son, John I of Schauenburg. Being a part of Holstein, Kiel belonged to the Holy Roman Empire and was situated only a few kilometres south of the Danish border.
Kiel, the capital of the county (later duchy) of Holstein, was a member of the Hanseatic League from 1284 until it was expelled in 1518 for harbouring pirates. In 1431, the Kieler Umschlag (trade fair) was first held, which became the central market for goods and money in Schleswig-Holstein, until it began to lose significance from 1850 on, being held for the last time in 1900, until recently, when it has been restarted.
The University of Kiel was founded on 29 September 1665 by Christian Albert, Duke of Holstein-Gottorp. A number of important scholars, including Theodor Mommsen, Felix Jacoby, Hans Geiger and Max Planck, studied or taught there.
Schleswig-Holstein with Kiel Fjord at the Baltic Coast.
From 1773 to 1864, the town belonged to the king of Denmark. However, because the king ruled Holstein as a fief of the Holy Roman Empire only through a personal union, the town was not incorporated as part of Denmark proper. Thus Kiel belonged to Germany, but it was ruled by the Danish king. Even though the empire was abolished in 1806, the Danish king continued to rule Kiel only through his position as Duke of Holstein, which became a member of the German Confederation in 1815. When Schleswig and Holstein rebelled against Denmark in 1848 (the First Schleswig War), Kiel became the capital of Schleswig-Holstein until the Danish victory in 1850.
During the Second Schleswig War in 1864, Kiel and the rest of the duchies of Schleswig and Holstein were conquered by a German Confederation alliance of the Austrian Empire and the Kingdom of Prussia. After the war, Kiel was briefly administered by both the Austrians and the Prussians, but the Austro-Prussian War in 1866 led to the formation of the Province of Schleswig-Holstein and the annexation of Kiel by Prussia in 1867. On 24 March 1865 King William I based Prussia's Baltic Sea fleet in Kiel instead of Danzig (Gdańsk). The Imperial shipyard Kiel was established in 1867 in the town.
When William I of Prussia became Emperor William I of the German Empire in 1871, he designated Kiel and Wilhelmshaven as Reichskriegshäfen ("Imperial War Harbours"). The prestigious Kiel Yacht Club was established in 1887 with Prince Henry of Prussia as its patron. Emperor Wilhelm II became its commodore in 1891.
Because of its new role as Germany's main naval base, Kiel very quickly increased in size in the following years, from 18,770 in 1864 to about 200,000 in 1910. Much of the old town centre and other surroundings were levelled and redeveloped to provide for the growing city. The Kiel tramway network, opened in 1881, had been enlarged to 10 lines, with a total route length of 40 km (25 mi), before the end of the First World War.
Kiel was the site of the sailors' mutiny which sparked the German Revolution in late 1918. Just before the end of the First World War, the German fleet stationed at Kiel was ordered to be sent out on a last great battle with the Royal Navy. The sailors, who thought of this as a suicide mission which would have no effect on the outcome of the war, decided they had nothing to lose and refused to leave the safety of the port. The sailors' actions and the lack of response of the government to them, fuelled by an increasingly critical view of the Kaiser, sparked a revolution which caused the abolition of the monarchy and the creation of the Weimar Republic.
During the Second World War, Kiel remained one of the major naval bases and shipbuilding centres of the German Reich. There was also a slave labour camp for the local industry. Because of its status as a naval port and as production site for submarines, Kiel was heavily bombed by the Allies during the Second World War. The bombing destroyed more than 80% of the remaining old town, 72% of the central residential areas, and 83% of the industrial areas. During the RAF bombing of 23/24 July 1944, Luftwaffe fighters tried to intercept the spoof (i.e. decoy) force instead of the main force attacking Kiel, and there was no water for three days; trains and buses did not run for eight days and there was no gas available for cooking for three weeks. There were several bombing raids of the port area during the period 20 February – 20 April 1945 which successfully eliminated many U-Boats, and the few large warships (cruisers Hipper, Scheer, and Köln) still afloat at that time. Although the town was beyond the stop-line set for the western Allies in the German surrender at Lüneburg Heath, it and its port, its scientists, and the canal were seized by a British T-Force led by Major Tony Hibbert on 5 May 1945. This forestalled capture of the town by the Soviets, whom the Allies expected to advance from Germany to Denmark in violation of the Yalta agreement.
Just like other heavily bombed German cities, the city was rebuilt after the war. In 1946, Kiel was named the seat of government for Schleswig-Holstein, and it officially became the state's capital in 1952.
Today, Kiel is once again an important maritime centre of Germany, with high-tech shipbuilding, submarine construction and one of the three leading institutions in the field of marine sciences in Europe, the IFM-GEOMAR. Regular ferries to Scandinavia and Lithuania, as well as the largest sailing event in the world called the Kiel Week (Kieler Woche) in German and The Kiel Regatta in English. The Kieler Umschlag is another festival, which has been taking place again since 1975. Kiel is also home to a large service sector and a number of research institutions including the University of Kiel, which is the oldest, largest, and most prestigious university in the state.