Campbell was first choice for the role by casting director Joe D'Agosta, who had worked with him before and believed he could do it. Campbell was mostly known for thugs, killers, and rapists at the time, particularly for playing Caryl Chessman. Campbell was eager to show he had more range, and Trelane was the type of character any actor would have jumped at.Funny, I always though the opposite. He was supposed to be effete, childish, a boor in Squire, and in this he was perfect.The late William Campbell was good as a Klingon in 'Tribbles', but his acting ability in the Squire of Gothos disappointed me.