William Og de Burgh (1240-1270) was an Anglo-Irish noble who reigned as Earl of Ulster under King Henry III of England, succeeding Hugh de Lacy, 1st Earl of Ulster and preceding Richard Og de Burgh, 2nd Earl of Ulster.
Biography[]
William Og de Burgh was born in 1240, the son of Richard Mor de Burgh. William served with honor as a knight in King Henry III of England's army during the king's campaigns in France and Scotland. During the king's wars in Ireland, William de Burgh slew the Lord of Desmond during his campaigns on the island, only to be killed in battle at Ath an Chip (Athankip) by the forces of the Kingdom of Connacht in 1270.