He was the son of Major Thomas Brooke Sr. and Esquire and his second wife Eleanor Hatton who later remarried Col. Henry Darnall.

[1] He was grandson of the Reverend Robert Brooke Sr., who had similarly held the office briefly during the Cromwellian period in 1652.

He was nominated by Charles Calvert, 3rd Lord Baltimore to become a member of the first royal Council, commonly known as the Upper House, on August 26, 1691.

Thomas was dismissed from all offices by the Governor of Maryland, John Seymour, in 1708 as a result of close Roman Catholic ties—his brothers were Jesuits and Col. Henry Darnall was his stepfather—and for poor Council attendance, although his attendance had been very regular prior to Seymour's governorship.

Thomas resided at "Brookefield", his estate on Mattaponi Creek near the Patuxent River, which he inherited from his father.

At the time of his death on January 7, 1731, at "Brookefield", Thomas had amassed over 7,000 acres (28 km2) of land, in which a majority was heavily mortgaged.

[5][6][7] Following his first wife's death in 1692,[8][9] Brooke married Barbara Dent—the daughter of Col. Thomas Dent Sr. and Rebecca Wilkinson—by 1699.