Trekkies are celebrating a second birthday this week as original Enterprise crew member Leonard Nimoy turned 80 yesterday, March 26th. William Shatner, who played Captain Kirk in the original Star Trek, passed the same milestone on Tuesday.

Nimoy was born in Boston in 1931. He began his acting career as a child and after serving the Army reserves, he returned, making the rounds in early TV series like Dragnet, Bonanza and Get Smart. Nimoy and Shatner worked together for the first time in 1964 on an episode of The Man From U.N.C.L.E., playing opposing secret agents in the Cold War.

Unlike Shatner, Nimoy was cast in the original Star Trek pilot and retained his role on the second pilot. Nimoy played Mr. Spock in all 79 episodes from 1966-1969. He received three Emmy nominations for the portrayal, but no wins. He reprised his role in the short-lived animated series and all six of the original-cast Star Trek movies, and directed the third and fourth films.

Again in contrast to Shatner, Nimoy has been a constant figure in the Star Trek universe for over forty years. He appeared in a crucial arc when the franchise was reinvigorated in Star Trek: The Next Generation. By that point in the timeline, Spock had become an ambassador to the Romulans (Vulcans live even longer than sci-fi actors).

He was also the only original cast member besides Majel Barrett (who voiced the ship’s computer) to return for the reboot in 2009. Spock and Nimoy were the thread that connected the original series to the new, alternate version, where Zachary Quinto takes over the role of “young Spock”.

Nimoy struggled with the attention he got from Star Trek for decades, feeling that his more serious work was being ignored. In 1977 he wrote the autobiography I Am Not Spock. He eventually got over this frustration, though – in 1995 he wrote a second book entitled I Am Spock.

His role in Star Trek has cemented Nimoy as a pillar of geek culture, and allowed him to be a staple of science fiction television and movies for decades. Aside from playing himself in over a hundred TV shows and specials, he provided voices for animated movies like The Pagemaster and Atlantis: The Lost Empire and several video games. Nimoy’s last turn at the science terminal was in the MMORPG Star Trek Online.

Today, Nimoy is still appearing at science fiction events and guest-starring on TV shows like Futurama. None has been a more happy or frequent user of his talent than Fringe (recently renewed for a 4th season), where he plays dimension-hopping genius William Bell. Unsubstantiated rumors mention Nimoy as a possible contender for the voice of Smaug the dragon in upcoming The Hobbit movies.

Happy birthday, Leonard. You are, and always shall be, my favorite.