膠州湾
In 1860, a Prussian expeditionary fleet arrived in Asia and explored the region around Jiaozhou Bay. The following year, the Prussian-Chinese Treaty of Peking was signed. After journeys to China between 1868 and 1871, the geographer Baron Ferdinand von Richthofen recommended the Bay of Jiaozhou as a possible naval base. In 1896 Rear Admiral Alfred von Tirpitz, at that time commander of the East Asian Cruiser Division, examined the area personally as well as three additional sites in China for the establishment of a naval base. Rear Admiral Otto von Diederichs replaced Tirpitz in East Asia and focused on Jiaozhou Bay even though the Berlin admiralty had not formally decided on a base location.