or Western Bug River
River, eastern central Poland.
Rising in western Ukraine, it flows north along the Poland-Ukraine and Poland-Belarus borders to Brest, and turns west into Poland to the Vistula River north of Warsaw , running a total of 481 mi (774 km). It is navigable below Brest. In World War I several battles were fought along its course in 1915. About 200 mi (322 km) of its central course formed part of the Curzon Line . This same section was included in the 1939 Russo-German boundary, and largely retained after World War II in the boundary between the U.S.S.R. and Poland.