膠州湾
In the early 1890s, the German Empire had been considering occupying Jiaozhou Bay ("Jiaozhou" was formerly romanized as Kiaochow, Kiauchau or Kiao-Chau in English and Kiautschou in German) for building its first naval base in East Asia in order to expand into the interior of Shandong. In 1891 the Qing government decided to make Qingdao (commonly spelled "Tsingtao" until well into the 20th century) defensible against naval attack and began to improve the existing fortifications of the town. German naval officials observed and reported on this Chinese activity during a formal survey of Jiaozhou Bay in May 1897. In November 1897, the German Navy seized Jiaozhou Bay under the pretext of ensuring that reparations were paid for the murder of two German Catholic missionaries in the province. In the spring of 1898, the German government signed a treaty that allowed the Germans to lease an area of for 99 years, to construct a railway to Jinan, the capital of Shandong province, and to exploit coalfields along the railroad.