Nicholas Courtney,has passed away at the age of 81

Follow @cadlymack on TwitterNicholas Courtney, best known for his role as Brigadier in the UK's original "Doctor Who" series, has passed away at the age of 81. Courtney actually worked with more versions of the Doctor than any other actor, having appeared in 107 episodes of the sci-fi series, several TV shorts, and reprising the role of Brigadier in "The Sarah Jane Adventures."

Born in Cairo, Egypt on Dec. 16, 1929 as William Nicholas Stone Courtney, Courtney served in the British Army before becoming an actor. Before breaking out on "Doctor Who," Courtney was in several cult hit television series.

He first appeared on "Doctor Who" in 1965 in "The Dalek's Master Plan." Ultimately, when David Langton gave up the role of Brigadier Alistair Gordon Lethbridge-Stewart, Courtney was cast in the role, which became his best-known "Doctor Who" role.

Courtney, whose most recent acting credit is 2009's "Liberty Hall" short (as Lethbridge-Stewart) was also an accomplished writers. He's published memoirs "Five Rounds Rapid!," "A Soldier in Time," and "Still Getting Away With It"

The Brig and the Sergeant Major make brief (unnamed but recognisable) appearances in John M Ford's hilarious "Star Trek" novel, "How Much for Just the Planet".