He was a gay man who could not live as a gay man, because of the fact that homosexuality was a crime in the UK at that time (a prime example was that of Oscar Wilde being locked up in prison for many years due to that).
He arrived at Downton Abbey, a castle estate in Yorkshire, England in 1910 but he was under a cloud from his arrival. Thomas, sometimes called Barrow, was originally the first footman, who had aspired to be a valet. He was played by UK actor, Robert James-Collier.
Thomas Barrow is the main antagonist, of the UK-US produced period drama, Downton Abbey, serving as one of the two main antagonists in Series 1-3 (alongside Miss O’Brien) and the main antagonist in Series 4-6. The usually scheming under-butler Thomas Barrow (Rob James-Collier) doing one of the rare unselfish things in his life by saving an unconscious Lady Edith (Laura Carmichael) from a fire in her bedroom.