Travers (Terror of the Vervoids)

Commodore "Tonker" Travers was the commanding officer of the Hyperion III in 2986. He helped the Sixth Doctor save his ship from the Black Hole of Tartarus, stop Rudge's hijacking attempt and defeat the Vervoids. (TV: Terror of the Vervoids)

He had previously encountered the Doctor and his companion Evelyn Smythe, to whom he proposed. She declined. (PROSE: Instruments of Darkness)

Behind the scenes
Tom Adams, George Baker, Ian Bannen, Keith Barron, John Carson, Frank Finlay, Ronald Fraser, Peter Gilmore, Richard Johnson, Patrick Stewart, Anthony Valentine and Frank Windsor were considered for the role before Michael Craig was cast.