Vorshak

Vorshak was the commander of Sea Base 4 in 2084.

He helped the Fifth Doctor fight the Silurians and Sea Devils who attempted to take over the base and later abort the missile launch. When Icthar tried to shoot the Doctor, Vorshak sacrificed his life by taking the blast himself. (TV: Warriors of the Deep)

Behind the scenes
Steven Berkoff, Brian Blessed, Kenneth Colley, Michael Craig, Paul Darrow, Anton Diffring, Peter Gilmore, Del Henney, Gareth Hunt, Martin Jarvis, Patrick Mower, David Warner, Simon Williams and Peter Wyngarde were considered for the role before Tom Adams was cast.