Magnusson, a journalist, author, and presenter, is best known for his 25 years of work on Mastermind, a show he called an “undemanding program for insomniac academics late at night.” His presence defined the program, a prime time BBC show watched by more than 22 million viewers, from 1972 until 1997.”Magnus Magnusson was one of the defining faces and voices of the BBC,” said Mark Thompson, the director general of the BBC. “To the contestants of Mastermind, he was a tough but always fair question-master, but behind this screen persona there was a family man of tremendous warmth and humanity.”

Magnusson, who focused on his writing career after Mastermind ratings began to slump and a new host took his place, first became ill in 2004 when he was hospitalized for emergency abdominal surgery. He recovered from this episode but was diagnosed with cancer last October, on his 77th birthday.

Magnusson, who coined the quiz show phrase, “I’ve started, so I’ll finish,” is survived by his wife of 52 years and his four children.