When he came on TV Howard's father told him to shut up and sit down. Sid Caesar, the TV pioneer and comic giant behind the legendary "Your Show of Shows," has died, his longtime friend and collaborator Carl Reiner has confirmed to Yahoo. Caesar was 91. It was another friend, TV host Larry King, who first reported the sad news on Twitter: Caesar won two Emmys and was nominated for six others for his landmark work in the 1950s. He picked up two more nods in the 1990s for guest-star work on the sitcoms "Mad About You" and "Love & War." In film, Caesar appeared in the all-star favorite "It's a Mad, Mad, Mad, Mad World," and played the football coach in "Grease" and its sequel, "Grease 2." [Photos: Check Out Pics From Sid Caesar's 1950s NBC Series 'Caesar's Hour']Along the way, Caesar sired a veritable comedy kingdom, helping nurture the careers of co-conspirators like Reiner, Mel Brooks, Neil Simon, Woody Allen, and "M*A*S*H" creator Larry Gelbart.