He was the second son of Frederick II, Duke of Legnica-Brzeg, by his second wife Sophie, daughter of Frederick I, Margrave of Brandenburg-Ansbach. After the death of his father in 1547, George II inherited the Duchy of Brzeg (which included the towns of Oława, Strzelin, Niemcza, Kluczbork, Byczyna, Wołów and Ścinawa).
During all his reign he maintain a good relationship to the Habsburgs (despite being a Lutheran) and was sent by the Emperor in some diplomatic missions. In 1548, George II took part in the coronation of Maximilian II in Prague and Bratislava, and also used the Bryeg army to maintain the internal order of the Duchy (Police Regulation of 1577). In particular, he dedicated himself to the expansion of his main residence, Brzeg, where he built a magnificent Renaissance palace, which was later destroyed by Frederick II the Great during the siege of Brzeg.
As a Lutheran, he was totally committed with the reforms started by his father.
He also built the Gymnasium (high school) in Brzeg (1564–1569) and, after the fire of Brzeg in 1569, the new City Hall and the towers of the Saint Nicholas Church.
