Unrestricted Submarine Warfare (jan 1, 1914 – may 31, 1915)
Description:
Germany pursued a highly effective U-boat campaign against merchant ships. On 4 February 1915, Germany declared a war zone around Britain, within which merchant ships were sunk without warning.Added to timeline:
Date:
jan 1, 1914
may 31, 1915
~ 1 years and 4 months