Spock, played by Leonard Nimoy, was a mainstay of Star Trek from the Original Series until Star Trek: The Undiscovered Country.
For many, he's not only the original, but best, and no emotional robot or hyper-efficient ex-Borg can ever take his place.
Here's some super Spock facts for you Leonard-lovers out there.
Spock was half-human, the child of Sarek, a Vulcan diploman, and Amanda Grayson, a human schoolteacher. Throughout his life he struggled to reconcile the two sides of his personality - logic and emotion.
Leonard Nimoy directed two Star Trek films - The Search for Spock and The Voyage Home, as well as the 1987 comedy Three Men and a Baby.
As a child, Spock owned a pet sehlat, a Vulcan animal similar to a teddy-bear in appearance.
A man of musical as well as many other talents, Leonard Nimoy has released several albums. His best known track is his 1969 homage to a hobbit, The Ballad of Bilbo Baggins.
Spock was the first ever Vulcan to join Starfleet, and had the Starfleet service number S179-276. He originally joined the Enterprise under Captain Pike, and worked as Science Officer under Captain Kirk.
Spock and Kirk often relaxed by playing tri-dimensional chess. Spock was also skilled at playing the Vulcan lute.
Several enduring elements of Vulcan behaviour, such as the Vulcan nerve pinch, were improvised by Leonard Nimoy. He also created the Vulcan salute, basing it on a traditional Jewish religious gesture.
Leonard Nimoy's father owned a barber shop, where, apparently, one of the popular styles on offer was the "Spock cut".
Being half-Vulcan, Spock had green blood, of the group T-negative.
Spock's final Trek television appearance was on the Next Generation episodes Unification parts one and two, in which he finally discovered the love of his father, Sarek.