Thomas Bourke, 4th Baron Bourke of Castleconnell, held his title for only a matter of hours on February 28, 1599. He was the son of Theobald Bourke (died August 19, 1578), a principal commander against Lord Desmond, and his wife Mary, daughter of Donough O'Brien, Earl of Thomond, and grandson of Sir William Bourke (created Baron Bourke of Castleconnell by Elizabeth I by patent dated May 16, 1580). Thomas had been preceded as Baron Bourke of Castleconnell by his two elder brothers, John (who sat in parliament in Dublin in 1585 and was slain in battle at Hounslow, Middlesex on January 14, 1592, leaving no issue) and Richard (slain in battle by Dermot O'Connor Sligo at Ballynecargy, County Limerick on February 28, 1599, also leaving no issue).
At his death, Thomas left a daughter, Christina (wife of Sir Dominick White, Mayor of Limerick in 1636, later created Count of Alby and Marquis of Albeville in the Holy Roman Empire), and an infant son, Edmund Bourke, 5th Lord Bourke of Castleconnell. During his youth, Theobald, younger brother of Thomas, usurped the title of Baron Bourke of Castleconnell, claiming that Edmund was illegitimate. Theobald was later created Baron of Brittas in 1618, and Edmund, having established his legitimacy, continued the line of the Barons of Castleconnell.
Burke, Sir Bernard (Ulster King of Arms), A Genealogical History of the Dormant, Abeyant, Forfeited and Extinct Peerages of the British Empire, Burke's Peerage, Ltd., 1883, pp. 67–68.