John de Burgh (1286–1313)

John de Burgh (1286 – 18 June 1313) was the son of Richard Óg de Burgh, 2nd Earl of Ulster and Margaret de Burgh.

Heir apparent to the Earldom of Ulster, he married (as her first husband) in Waltham Abbey, Essex, on September 30, 1308, Elizabeth de Clare, sister of Earl of Gloucester and Hertford. She was the founder of Clare College, Cambridge, and a granddaughter of King Edward I of England. Gloucester in turn married John's sister Matilda.

John and Elizabeth had one son:

• William Donn de Burgh, 3rd Earl of Ulster (1312–1333)

However, he died in Galway the next year, leaving his infant son William heir apparent to the Earldom.