It was thought until recently that Thomas's father Edward Burgh, 2nd Baron Burgh, had married Catherine Parr in 1529, but the 2nd Baron died in August 1528. Through the recent research of contemporaneous documents, including the will of Catherine's mother, by the biographers Susan E. James, Linda Porter, David Starkey, and Alison Weir, it has been established that she married the 2nd Baron's grandson, who shared his grandfather's first name. Sir Edward Borough was the eldest son of Sir Thomas Borough. In the will of Maud Parr dated May 1529, she mentioned Sir Thomas, father of Edward, saying "I am indebted to Sir Thomas Borough, knight, for the marriage of my daughter". At the time of his son's marriage, Thomas was thirty-five, which would have made Edward around Catherine's age. Sir Edward was in his twenties and may have been in poor health. He served as a feoffee for Thomas Kiddell and as a justice of the peace. According to Susan James and Linda Porter, Sir Edward Borough died in the spring of 1533, never holding the title of Lord Borough. Other sources state "before April 1533".