William Donn de Burgh, 3rd Earl of Ulster (b. 1312)
William de Burgh, 3rd Earl of Ulster and 4th Baron of Connaught (English: ; d’-BER; 17 September 1312 – 6 June 1333) was an Irish noble who was Lieutenant of Ireland (1331–2) and whose murder, aged 20, led to the Burke Civil War.