Final answer:
In the historical context of the German Empire's sphere of influence, Germany controlled the region now known as Tanzania in Africa and Jiaozhou Bay in China, but they were forced to relinquish these territories after World War I due to the Treaty of Versailles.
Step-by-step explanation:
The geographic feature within the German sphere of influence that is notable in a historical context is the region of what is now Tanzania. During the late 19th century, Germany gained control of this area in the scramble for African territory. The port that the Germans controlled was Jiaozhou Bay, located on the Shandong Peninsula along the coast of China. They received this as part of their colonial presence and influence along the Yangtze River Valley to the north.
After World War I, following the Treaty of Versailles, Germany was forced to relinquish its colony in Tanzania to Britain. This was part of the broader context of Germany losing territories and colonies as a result of its defeat in the war. Germany's losses also included European territories and other colonies in Asia and Africa such as the territories in the Yellow River Valley and the port on Shandong Peninsula.