county of Ulster" (c. 1255) in consequence of which he was styled later Earl of Ulster. Walter, 1st Earl of Ulster was succeeded by his son, Richard Óg de Burgh, 2nd Earl of Ulster. In 1286, he ravaged and subdued Connaught, and deposed the chief native king (Bryan O'Neill), substituting how own nominee. He also attacked the native king of Connaught, in favour of that branch of the O'Conors whom his own family supported. He led his forces from Ireland to support Edward I in his Scottish campaigns, and on Edward Bruce's invasion of Ulster (1315), Richard marched against him, but had given his daughter, Elizabeth, in marriage (c. 1304) to Robert Bruce (afterwards Robert I, King of Scots). Occasionally summoned to English parliaments, he spent most of his forty years of activity in Ireland, where he was the greatest noble of his day, usually fighting the natives or his Anglo-Norman rivals. The patent roll of 1290 shows that in addition to his lands in Ulster, Connaught and Munster, he held the Isle of Man, but later surrendered it to the king. Richard, 2nd Earl's grandson and successor was William Donn de Burgh, 3rd Earl of Ulster (d. 1333), son of John de Burgh (d. 1313) and Elizabeth, Lady of Clare (d. 1360), sister and co-heir of the last Clare Earl of Hertford (d. 1314). William Donn married Maud of Lancaster (daughter of Henry, 3rd Earl of Lancaster) and was appointed Lieutenant of Ireland (1331), but was murdered in his 21st year, leaving his only daughter, Elizabeth de Burgh, as the sole heiress not only of the de Burgh possessions but of the vast Clare estates. She was married in childhood to Lionel, 1st Duke of Clarence (third son of Edward III) who was recognized in her right as Earl of Ulster from whom the Yorkist Plantagenets later derived their claim to the throne of England. Their descendant, Edward, 4th Duke of York, ascended the throne in 1461 as Edward IV, since when the Earldom of Ulster has been only held by members of the British Royal Family. Burke Civil War (1333–38) On the murder of William Donn de Burgh, 3rd Earl of Ulster (1333), his male kinsmen (who had a better right to the succession than his daughter, according to native Irish ideas), adopting Irish names and customs, became virtually native chieftains and succeeded in holding the bulk of