Spock was the half-Human, half-Vulcan executive/science officer of the USS Enterprise in the original series of Star Trek. One of the most respected and revered figures in the history of Starfleet and the United Federation of Planets, he has had a long and distinguished career as a science officer, an XO, a Starfleet Academy tutor, a captain and in his later years as an ambassador between the Federation and the Romulan Empire. He has enjoyed a close friendship with his commanding officer James T. Kirk and they have been on countless adventures together throughout their time on the original Enterprise, and have saved the galaxy more times than anyone dares to guess.
Spock has most notably been portrayed by veteran actor Leonard Nimoy in the original series, each of the Star Trek films I - VI, and in The Next Generation two-part episode "Unification". In J.J. Abrams' reboot of the Star Trek franchise, the character of Spock has been portrayed by Zachary Quinto.
Death and rebirth
The prime version of Spock would meet a tragic fate in Star Trek II: The Wrath of Khan. In early 2285, Spock, while on a training mission, ceded command of the Enterprise to Admiral Kirk during a mission that involved keeping the Genesis Device out of the hands of Khan Noonien Singh. When Khan armed the device after having been defeated by Kirk and the Enterprise, Spock sacrificed his own life by repairing the Enterprise's plasma conduits – in a severely irradiated portion of engineering – in order to save the crew. Following his funeral service, Spock's body was "buried" by being fired into space inside a torpedo casing.
During the events of Star Trek III: The Search For Spock, Spock's coffin landed on the surface of the Genesis Planet and the radiation emanating from the planet caused his cells to regenerate. Meanwhile, Kirk and the rest of the Enterprise's senior staff disobeyed Starfleet orders so that they could retrieve Spock's body, and discovered that he had been reborn as a child (and was quickly aging to adulthood), but whose mind was a complete blank. On Vulcan, Spock's living body (now at the age it had been when he died) was reunited with his katra (the Vulcan soul), which Spock himself had placed in Dr. Leonard McCoy prior to his death.
Spock has continued to serve Starfleet and the Federation ever since this ressurrection and has yet to meet his final end. Currently, this incarnation of Spock still lives on in the alternate reality of Star Trek created by J.J. Abrams, but maintains a low profile while his younger self serves alongside Jim Kirk aboard the USS Enterprise.