 During this period, World War I broke out in July 1914, though "Bremen" remained in the shipyard until 27 May 1915, when she was recommissioned.After completing sea trials, she was assigned to the naval forces stationed in the Baltic Sea.She left Kiel on 2 July and arrived in Libau six days later, where she joined the Reconnaissance Unit for the Baltic Sea Command under now-"Konteradmiral" Hopman.