Played "Dr. John H. Watson" in the BBC's radio dramatizations, adapted by Bert Coules, and others, of all the Sherlock Holmes novels and short stories. Broadcast from November 1989 to March 1995, Clive Merrison starred, alongside Williams, as the great detective. Every Sherlock Holmes novel and short story was dramatized starring these two.
He (as Dr. John H. Watson) and Clive Merrison (as Sherlock Holmes) are the only acting duo to complete the entire Conan Doyle canon of "Sherlock Holmes" stories.