Bug River at English => English (The Britannica Concise) Of Explained:
River, E central Poland. Rising in W 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.