Matt Decker Commodore Matthew " Matt " Decker was a Human Starfleet flag officer assigned as the commander of the . History . By 2256 , Decker was considered one of Starfleet ' s most decorated captain s , listed among other legends such as Robert April , Christopher Pike , Philippa Georgiou , and Jonathan Archer . ( ) In 2267 , the " Constellation " was on a routine survey mission near system L - 374 when it encountered an alien planet killer systematically destroying the planet s of the system . During the encounter , Decker ' s ship became hopelessly damaged , rendering all power plants dead . Decker remained on board to confront the machine , beam ing his entire crew to what he believed was safety on L - 374 III , the third planet of the L - 374 system . When the alien machine destroyed that planet , and further damaged the " Constellation " , Decker was the only survivor . Decker was later discovered by the , which transported him aboard from his broken ship . He initially resisted the effort to do so , stating that he had never lost a command before . Consumed with grief over his actions , and with an almost reckless desire for revenge , Decker seized command of the " Enterprise " after losing contact with the " Constellation " , leaving Captain Kirk stranded aboard the " Constellation " . Decker then launched an attack on the planet killer in an attempt to stop it from reaching " the most densely populated sector of our galaxy . " His attack turned out to be a futile move which resulted in severe damage to the " Enterprise " . When communications were restored with the " Constellation " , Captain Kirk gave Commander Spock a direct order to relieve Decker , on Kirk ' s personal authority , as captain of the " Enterprise " . Decker submitted to Spock ' s relieving him of command after being threatened with arrest if he did not comply . Decker subsequently stole the " Enterprise " shuttlecraft " " , piloting it into the maw of the machine , in a suicide attempt . Decker was killed in the attempt . While the attack failed to cause significant damage – the planet killer had lost a small amount of power – it did demonstrate to the " Enterprise " crew how to disable the machine . Kirk drove the " Constellation " into the maw of the planet killer , which died when it was unable to handle the energy released by the " Constellation " s exploding impulse engine s . Following the battle , Captain Kirk noted in that Decker had given his life in the line of duty . ( ) Decker ' s assumption of command of the " Enterprise " later became a Federation precedent . ( , " okudagram " ) Appendices . Background information . Matthew Decker was played by actor William Windom . The character of Matthew Decker was devised by writer Norman Spinrad . The producers of initially asked him to write a part for Robert Ryan . Intending to take inspiration for the plot of from the story of " Moby Dick " , Spinrad developed the role as being similar to Captain Ahab . The character was intentionally made less intense after William Windom was instead cast as Matt Decker . Stated Spinrad , " " Things had to be adjusted . I had to make him a little softer , and I think it might have taken some of the edge off of the story . In the original version , Commodore Decker was much stronger . They don ' t find him slumped over in the ruined ship . Instead , they find him staring out the viewscreen and in a " very " bad mood . There was also the feeling that a guest star with that kind of presence would overshadow Captain Kirk , and therefore his character had to be toned down and his lines reduced . " " ( " " , p . 48 ) In the second revised final draft script of " The Doomsday Machine " , this character was called " Curt Decker " in the cast list , and " Matt Decker " in the rest of the script . In an excerpt from the writer ' s guide to featured in " " – Susan Sackett and Gene Roddenberry ' s book about the movie – Matt Decker is established as the father of Will Decker . Similarly , for the entry about Williard Decker ( Will Decker ) in the , he is identified as the son of Matt Decker . In a background note for this entry , the authors state that Paramount publicity materials for the first movie suggested the existence of this relationship . Apocrypha . In the novel " Vendetta " – essentially a " sequel " to both " The Doomsday Machine " and the episode – it is revealed that Jean - Luc Picard was assigned to research Matt Decker ' s career while he was at Starfleet Academy , with the limited available details of the conflict with the planet killer causing Picard to assume that Decker took the " Constellation " into the planet killer himself , rather than his failed attempt to attack it with a shuttlecraft . In James Blish ' s adaptation of " The Doomsday Machine " , Decker ' s first name is " Brand " and , in common with the episode ' s majority of earlier script drafts , he doesn ' t pilot the shuttlecraft into the planet killer . In addition , after Decker orders McCoy off the bridge with the statement , " " Mr . Spock knows his duties under regulations , doctor . . . do " you " ? " " Blish gives McCoy one final retort : " " Yes , sir – go to sickbay and wait for the casualties you ' re about to send me . " " The RPG supplement " Star Trek IV Sourcebook Update " gives his full name as " Matthew Brand Decker " . Several other members of the Decker family are featured in the . In the book " " by David A . Goodman , the eighty - year - old " Marshall " - class ship " Patton " was taken out of mothballs , refitted and re - armed , and placed under the command of then - Lieutenant Commander Matthew Decker as a part of a Starfleet scout mission protecting the Asteroid Prospectors Association ( APA ) in the Disputed Area near Klingon space . On the fifth planet of the Donatu star system within the Disputed Area , the APA discovered a rich deposit of dilithium in 2242 , and a prospecting station was set up . This drew the attention of three Klingon ships under the command of Captain Klaar , who was bent on removing the Federation presence on Donatu V . Outgunned , Decker , aboard " Patton " , and Commodore ( later Admiral ) José I . Mendez , commanding the " Eisenhower " , dove their ships in and out of Donatu V ' s heavily cloud ed atmosphere at warp speed s , firing multiple volleys at the unsuspecting Klingons . This brilliant attack bought just enough time for two " Baton Rouge " - class ships to arrive and help chase the Klingons away , and was the decisive action which convinced the Federation Council to commission a fleet of twelve " Constitution " - class starships , conceived and proposed by Robert April . Decker ' s first meeting with Kirk is detailed in " The Brave and the Bold , Book One " , as the " Enterprise " and " Constellation " join forces to combat a deadly plague . Decker ' s mirror universe counterpart appears in " The Sorrows of Empire " , succeeding the mirror Garth of Izar as Grand Admiral of the , with the ISS " Constellation " ( which survives long enough to be refitted , like the " Enterprise " ) as his flagship . He is killed in a mutiny instigated by in 2277 .