https://en.wikipedia.org/wiki/John_de_Burgh_(died_1313)
WebMargaret de Burgh. John de Burgh ( English: / dˈbɜːr /; d’-BER; 1286 – 18 June 1313) was an Irish noble who was the son of Richard Óg de Burgh, 2nd Earl of Ulster, and Margaret de Burgh. Waltham Abbey Church, Essex. Heir apparent to the Earldom of Ulster, he married (as her first husband) in Waltham Abbey, Essex, on 30 September 1308 ...