I wanted to add my thoughts on the passing of Nicholas Courtney.
As Richard mentioned, Nicholas played Brigadier Lethbridge-Stewart in Doctor Who. His first appearance in the role was in 1968 (he previously appeared as a different character). He became a regular character in the early 70s and returned for guest appearances in 80s and 90s. His final appearance in the role was in the spin off series The Sarah Jane Adventures in 2008.
He also regularly attended Doctor Who events and was always enthusiastic about the show, unfortunately neither me or Richard had the chance to meet him though.
Its no understatement to say that Nick was a huge part of the show and he will be sorely missed.