The province was a battleground in 1914-15, when, following the outbreak of the [[First World War]] Russian armies invaded the province but were decisively defeated at the [[Battle of Tannenberg]] in 1914 and the Battle of the Masurian Lakes. Following Germany's defeat in 1918, East Prussia remained part of [[Germany]] (with the exception of the port of [[Memel]], seized by newly-independent [[Lithuania]]), but was separated from the rest of the country by a strip of Polish territory known as the [[Polish Corridor]]. In 1939 [[Nazi]] Germany forced Lithuania to relinquish Memel. | The province was a battleground in 1914-15, when, following the outbreak of the [[First World War]] Russian armies invaded the province but were decisively defeated at the [[Battle of Tannenberg]] in 1914 and the Battle of the Masurian Lakes. Following Germany's defeat in 1918, East Prussia remained part of [[Germany]] (with the exception of the port of [[Memel]], seized by newly-independent [[Lithuania]]), but was separated from the rest of the country by a strip of Polish territory known as the [[Polish Corridor]]. In 1939 [[Nazi]] Germany forced Lithuania to relinquish Memel. |