Of all his endeavours, acting was undoubtedly the most successful. And of all his roles, one stood out, head, shoulders and pointed ears above the rest: that of Mr Spock, the half-human, half-Vulcan first officer of the USS Enterprise in Star Trek.

As Mr Spock, along with Captain Kirk and his valiant crew Scott, Bones, Uhura, Sulu and Chekov, Nimoy went boldly where no man had gone before, into outer space, and to the giddy heights of fandom almost unequalled in popular culture.

Nimoy's Spock starred in Star Trek: The Original Series, Star Trek: The Animated Series, a series of Star Trek feature films in the 1980s, a guest appearance in Star Trek: The Next Generation and, finally, a role in the recent J.J. Abrams reboot of the Star Trek franchise.

In that rare and intangible way, actor and character became one. Even when Nimoy threatened not to return to the role, and Star Trek's creator Gene Roddenberry hatched plans to replace him with another Vulcan, Nimoy ultimately relented.

On some deeper level, he understood better than anyone, that his destiny, and his connection to that role, was inescapable.

A life is like a garden. Perfect moments can be had, but not preserved, except in memory. LLAP — Leonard Nimoy (@TheRealNimoy) February 23, 2015

As was ours to the character itself: the logical half of of Captain Kirk's conscience. (The other half was the highly emotional Doctor McCoy.) Their clashes of ideology, and Captain Kirk's reasoned moderation of their debates, became one of the enduring hallmarks of the Star Trek story.

Nimoy's life began long before the USS Enterprise blasted off to save the Federation from the Klingons (and the Romulans), in the very Earth-bound city of Boston, where he was born on March 26, 1931.

His father was a barber who had escaped war-scarred Europe. When Nimoy ran away to Hollywood, his family were startled, if not actually disappointed. He had, after all, abandoned a scholarship to Boston College, for what?

Worse, his career did not fire up as he had hoped. He got one small, in a film too unmemorable to mention, and then ended up quitting Hollywood to join the army.

In the 1960s, however, he returned and, instead of film, pushed into television.

A handful of small roles in such as Sea Hunt and Wagon Train led to a leading role in The Lieutenant. Its producer Gene Roddenberry liked what he saw and, when he was casting for his new series, Star Trek, offered Nimoy a starring position.

Success sat easily with Nimoy, though his connection to Mr Spock did not, at least not always. In 1975 he published a memoir titled I Am Not Spock, though the title makes a far more provocative point that the prose did.

Two decades later, in 1995, he published a second memoir, this one titled I Am Spock.

Again the title makes more of the issue that the book does, but it does reflect Nimoy's concession to the fact that he, and the logical, sensible, seemingly unemotional Mr Spock would be inextricably linked.

Don't smoke. I did. Wish I never had. LLAP — Leonard Nimoy (@TheRealNimoy) January 11, 2015

Ironically, Star Trek was not an outright success at the time. It was only in the 1970s, when the series was heavily repeated on US television, that a passionate fandom was born.

Out of that sprang conventions, merchandise and a series of motion pictures which put the crew of the starship Enterprise at the zenith of popular culture. It also blazed a trail in a hitherto unexplored aspect of studio business: merchandise.

There were of course, many other aspects of Nimoy's acting work. The television drama A Woman Called Golda. A career as a film director, notably two of the Star Trek films as well as Three Men and a Baby in 1987 and The Good Mother in 1988.

And there were even the strange and surreal moments, such as a series of albums from the 1960s and 1970s including The Touch of Leonard Nimoy, The New World of Leonard Nimoy and Leonard Nimoy Presents Mr Spock's Music from Outer Space.

As an actor, Nimoy had the rare honour of rehearsing his death countless times, in countless roles. On stage, on television and on film.

He even died as Spock, famously electing to sacrifice himself by entering a radiation soaked part of the ship's engine room so he could repair its engines and allow it to warp to safety in Star Trek II: The Wrath of Khan.

"The needs of the many," he said, as he lay dying, "outweigh the needs of the few. Or the one."

A movie scene: stranger lands on earth. Hits buttons on a small device. All guns on earth are melted . He leaves. LLAP — Leonard Nimoy (@TheRealNimoy) January 10, 2015

Of course, in Hollywood, death is meaningless, and Spock returned in the next film - Star Trek III: The Search for Spock - to fight another day. (For the record, his jettisoned remains were regenerated by the unique properties of the planet on which he was laid to rest. But you knew that.)

But not before Captain Kirk could eulogise him, while the tear-stained officers of the Enterprise looked on.

"Of my friend, I can only say this," Captain Kirk said. "Of all the souls I have encountered in my travels, his was the most ... human."

Nimoy died at his home in Bel Air in Los Angeles, from end-stage chronic obstructive pulmonary disease, after being hospitalised briefly.

Few epithets seem more appropriate than the greeting most used by Nimoy's logical, but beautifully flawed, alter-ego: "Live long and prosper"; or, as it is said in the original Vulcan: "Dif-tor heh smusma."

To which we can only offer its traditional reply: peace and long life.

The spirit of Spock will live long and prosper. #RIPLeonardNimoy #LLAP pic.twitter.com/WyqQgTNDod — The White House (@WhiteHouse) February 27, 2015