William de Burgh (circa 1160 - winter 1205/1206) was the founder of the de Burgh/Burke/Bourke dynasty in Ireland. His family were in England for a while and claimed to descend from the French noble Counts of Rethel and Baldwin II of Jerusalem; however, their genealogists may have fabricated this.
Read more about William De Burgh: In Ireland, Marriage and Alliance, Connacht, Death, Family