Though largely overlooked, Prinz Eitel Friedrich was, after SS Kronprinz Wilhelm, the most successful of Germany's first wave of auxiliary cruisers.

On the eve of war in August 1914 she was at Shanghai, with orders to proceed to the German naval base at Qingdao for conversion as an auxiliary cruiser (Hilfskreuzer).

[2]: 72 At Qingdao Prinz Eitel Friedrich was equipped for her role as a commerce raider, receiving the armaments and crews of the aging gunboats Luchs, and Tiger.

She was commissioned on 5 August 1914 and sailed from Qingdao the same day to join company with Admiral Graf von Spee and the German East Asia Squadron.

[2]: 72 In the following seven months she operated in the Pacific and South Atlantic, sinking 11 vessels, mostly sailing ships, for a total of 33,423 gross register tons (GRT).