(written from a Production point of view)
Malachi Throne (1 December 1928 – 13 March 2013; age 84) was an actor from New York who appeared in three episodes of Star Trek: The Original Series and two episodes of Star Trek: The Next Generation.
Throne was Gene Roddenberry's first choice for the role of Doctor Philip Boyce for the first Star Trek pilot, "The Cage", however he turned down the role not wanting to play "the third man" next to the hero and his sidekick. However, Throne expressed interest in playing Spock, but Leonard Nimoy was already contracted to play the part by then. Roddenberry finally offered him the chance to provide the voice for the Talosian Keeper (physically portrayed by Meg Wyllie), which Throne accepted. Almost two years later, Throne was cast as Commodore Mendez for the "envelope" portions of "The Menagerie" two-parter. His voice for The Keeper had to be electronically pitch-altered so the audience wouldn't recognize it as the same actor who played Mendez. (These Are the Voyages: TOS Season Two)
Along with Gene Lesser he submitted a story idea for Star Trek called "The V.I.P.s". It did not go beyond a few bits of correspondence back and forth. 
He was with Leonard Nimoy for both his first (the first Star Trek pilot, "The Cage") and last (the Star Trek: The Next Generation episode "Unification II") Star Trek appearances on television. He also appeared in two other productions with Leonard Nimoy: Mission: Impossible (1967, 1969, also with Lee Meriwether, Vic Perrin, Ed McCready and Paul Sorenson) and the TV movie Assault on the Wayne (1971, also with Lloyd Haynes and William Windom).
Throne filmed his scenes for "The Menagerie" between Tuesday 11 October 1966 and Tuesday 18 October 1966 on Desilu Stage 9 and 10. He filmed his scenes for the episodes "Unification I" and "Unification II" on Monday 9 September 1991, between Wednesday 11 September 1991 and Friday 13 September 1991, Tuesday 24 September 1991, and Thursday 26 September 1991 on Paramount Stage 9 and 16.
As a boy, he had success in a musical version of Tom Sawyer, and he would go on to train as an actor at Brooklyn College and Long Island University. In 1959, he left the stages of New York to try to make a career in film and television.
In 1965, Throne appeared in the Gene Roddenberry-produced unsold pilot Police Story, which also featured Steve Ihnat, Grace Lee Whitney, and DeForest Kelley. Between 1968 and 1969, Throne starred as "Noah Bain" on the series It Takes a Thief, which was produced by Gene Coon. The series featured guest stars Alfred Ryder, George Sawaya, Meg Wyllie, Rosemary Forsyth, Keye Luke, Robert Ito, Mark Lenard, Peter Brocco, Steve Ihnat, Lawrence Montaigne, Roger C. Carmel, Yvonne Craig, Ricardo Montalban, John Hoyt, Erik Holland, Brock Peters, George Takei, Michael Ansara, Teri Garr, Sally Kellerman, Anthony Caruso, Julie Newmar, Joseph Bernard, Whit Bissell, Kenneth Tobey, and William Campbell.
Throne was a popular casting choice by producer Irwin Allen, and appeared in all of Allen's television shows: three episodes of Voyage to the Bottom of the Sea (1965-1967, with Joseph Ruskin, Robert Sampson and Ron Stein), an episode of Lost in Space (1966, with Bill Mumy and Ted Cassidy), two episodes of The Time Tunnel (1966-1967, with James Darren, Whit Bissell, Lee Meriwether, John Crawford, Peter Brocco and Perry Lopez), and an episode of Land of the Giants (1970, with Don Marshall, Joseph Ruskin and Whit Bissell).
His other television credits include: The Outer Limits (1964, with William Shatner, James B. Sikking, Louie Elias, and Lawrence Montaigne), the role of "Joseph Ronaugh" on The Bionic Woman (1975, with Alan Oppenheimer and Paul Carr), the role of "Ali Baba" on The Krofft Supershow (1976-1978, with Jay Robinson and Frank Welker), and Project U.F.O. (1978, with Pamelyn Ferdin, Richard Derr, and Whit Bissell).
In 1995, Thorne portrayed the role of Centauri Prime Minister Malachi on Babylon 5's Hugo Award-winning episode "The Coming of Shadows" (Andreas Katsulas also co-starred in this episode). His character's assassination allows a war-mongering faction gain control of his planet's government. The ensuing war's consequences fuel the show's narrative arc for the remaining seasons.
He also appeared in the TV movies The Doomsday Flight (1966, with Celia Lovsky, Bert Remsen, and Michael Sarrazin), Code Name: Heraclitus (1967, with Ricardo Montalban and Chuck Courtney), It's a Bird, It's a Plane, It's Superman (1975, with Kenneth Mars), and Longarm (1988, with Daphne Ashbrook, Noble Willingham, and Rene Auberjonois). His film credits include the Muhammed Ali biopic The Greatest (1977, with David Huddleston, David Clennon, Lloyd Haynes, Skip Homeier, and Paul Winfield). In 1992, Throne portrayed William Campbell, Sr. on Melrose Place; his wife was played by Salome Jens.
In 2004, Throne portrayed Captain Korogh in the fan production Star Trek: New Voyages, episode "In Harms Way", which features Trek performers Barbara Luna, William Windom, James Cawley, Jeffery Quinn, Sam Witwer, and Leslie Hoffman. The episode was written by Doug Drexler.