From 1311-1675 Brzeg was the capital of a Lower Silesian duchy (Duchy of Brzeg) ruled by the Piast dynasty, a branch of the dukes of Lower Silesia, one of whom built a castle in 1341.
During World War II, 60% of Brieg was destroyed and many of the town's inhabitants died during the severe winter of 1944-5 as they fled from the advancing Red Army, in its entire history the war had brought the most severe destruction to the town.