Twenty-year-old William Donn de Burgh, 3rd Earl of Ulster, known as "the Brown Earl", was murdered by his household knights in June 1333 after he had starved to death his cousin and rival Sir Walter Liath de Burgh in the previous year (1332).
For safety, as an infant and a female heiress, she was taken by her mother to England as her lordships collapsed in a power struggle.
[1][2] Three members of the de Burgh family fought against each other in an attempt to preserve their own personal estates, and hold overall control of the massive de Burgh inheritance in Ireland.
They were: The eventual outcome of the war was the loss of almost all the de Burgh lands in Ulster, which was reconquered within a year by the Gaelic-Irish.
[3][4] The remaining de Burghs in Ireland fragmented into three distinct clans, all of which had several sub-septs.