The Siege of Tsingtao began when Japan declared war on Germany following the latter's invasion of Belgium, aligning with the Allies. A major part of Japan's strategy involved securing German possessions in the Pacific and China, specifically the fortified port of Tsingtao, located in Shandong province. The Japanese forces, under Vice Admiral Sadakichi Kato, quickly moved to impose a naval blockade intended to isolate Tsingtao, effectively preventing German ships from entering or leaving the area. This tactical blockade marked Japan's entry into World War I as a proactive military power allied with the Entente. Japan's naval power was showcased during this campaign, emphasizing the growing influence of its maritime capability on the global stage.

The blockade forced the garrison of Tsingtao, comprised of German and Austro-Hungarian troops, into a defensive position. As land and naval assets from Japan converged on Tsingtao, the siege began in earnest, with artillery bombardments and land assaults beginning shortly after. The siege lasted from late August 1914 until the eventual surrender of the German garrison in early November of the same year. Japan's success at Tsingtao enhanced its regional prestige and solidified its position as a dominant power in East Asia post-conflict, altering the balance of power in the region significantly.

Japan would go on to seize control of German territories in the Pacific, and this event is often seen as a stepping stone towards Japan's further expansionist policies in the years leading up to World War II. The victory also marked a critical moment in Japanese nationalism and military expansion, showcasing their capabilities to both domestic and international audiences.