Granath was born in Örgryte, Gothenburg, Sweden. He starred in a broad range of roles from comedic to dramatic. He was active as an actor and Director at the Royal Dramatic Theatre in Stockholm between the years 1987–2007. Prior to his passing he was set to play Buckingham in a production of Richard III at the Royal Dramatic Theatre. It was a revival of a popular production he had appeared in during in 2014.
