By 1914 the submarine was not a new weapon, having first been used 150 years earlier. By the start of WW1 all the major ...

In 1917, Germany announces it will wage unrestricted submarine warfare against all ships, including passenger carriers, in ...

Germany's unrestricted submarine warfare, however, was an intolerable affront to America's dignity and honor. At the start of 1917, British intelligence intercepted the Zimmerman telegram ...

A real threat to Britain's food supplies and Britain’s ability to continue the war effort came in 1916 when a new campaign of 'unrestricted submarine warfare' began with deadly effect ...