George William, Duke of Liegnitz
George William (), also known as George IV William (; 29 September 1660 – 21 November 1675) was the last Silesian duke of Legnica (Liegnitz) and Brzeg (Brieg) from 1672 until his death. He was the last male member of the Silesian Piast dynasty descending from Władysław II the Exile (1105–1159), as well as the last legitimate male member of the entire House of Piast. Family George William was the eldest but only surviving son of Duke Christian of Legnica-Brzeg (1618–1672) by his wife Louise (1631–1680), a daughter of the Ascanian prince John Casimir of Anhalt-Dessau. He had three siblings: Karolina of Legnica-Brieg (1652–1707), last Silesian Piast duchess, married to Frederick, Duke of Schleswig-Holstein-Sonderburg-Wiesenburg (1651–1724) in 1672; Louise (1657–1660); Christian Louis (1664). As the only surviving son, George William was the sole heir to his father's possessions. Duke Christian of Legnica-Brzeg had spent many years in exile in Poland and in the Duchy of Prussia during the Thirty Years' War, after George William's grandfather Duke John Christian of Brieg had fallen out of favour with the Habsburg emperor Ferdinand II. Duke Christian became sole ruler over the Silesian duchies of Legnica and Brzeg in 1664. After the abdication of King