Thomas King (May 9, 1869 - April 15, 1912) was the Coxswain (also known as the Master-at-arms) on the Titanic. He was responsible for keeping law and order on the ship.
He was called the third night of the voyage after three sailors thought Jack Dawson was trying to rape Rose DeWitt Bukater. He handcuffed Jack on the orders of George Rowe and Caledon Hockley. Rose stepped in and revealed that Jack had in fact saved her, though she lied that she was trying to view the propellers to hide the fact that she had been intending to jump to her death. Jack affirmed this version of events, and was released.
Two days later, Cal set a plot to get rid of Jack. Spicer Lovejoy dropped Cal's necklace in Jack's pocket without him noticing. When Cal claimed that the diamond had gone missing, King and steward Barnes searched Jack and found it in his pocket. Jack protested his innocence but was found to also be in possession of someone else's coat. Jack was handcuffed to a pipe in King's office, but King was soon forced to deal with a riot in second class after being warned by a commissioner. He left to deal with the situation, leaving the key to the handcuffs with Lovejoy instead.
King was hanging onto the railing at the ship's stern during the final moments of the sinking. Unable to hold on he fell to his death moments before the ship's final plunge.
Behind the scenes
He was portrayed by Ron Donachie. The character is not credited by name but only as the Master-at-arms. In real life there were two masters-at-arms on the ship. King perished while the other, Henry Bailey, survived. Therefore, it can be certain that the one featured in the film is supposed to be Thomas King, since his character perished. Although Donachie portrays the character with his (Donachie's) natural Scottish accent, the historical Thomas King was an Englishman.