During World War I, Germany’s U-boats engaged unrestricted submarine warfare, devastating attacks on British ships notably the Lusitania. Though first suspended, Germany’s policy of ...

By 1915, the North Sea was declared a war zone and U-boats adopted a policy of unrestricted submarine warfare. Germany publicly declared its submarines would destroy all enemy merchant vessels in ...

On May 7, 1915, the British ocean liner had just entered the German-declared “unrestricted submarine warfare” zone, which deemed any ship, even civilian and merchant ones, fair game for ...

The number of British ships destroyed by U-boats nearly tripled after Germany declared unrestricted submarine warfare Previously unseen pictures of German submarines stranded on the English coast ...

Jan. 31 (UPI) --On this date in history: In 1917, Germany announces it will wage unrestricted submarine warfare against all ships, including passenger carriers, in war-zone waters. In 1924 ...