Brian Clemens

Brian Horace Clemens (30 July 1931 – 10 January 2015) was an English screenwriter and television producer. He was best known for his work on the television shows "The Avengers" and "The Professionals". He also wrote and producer the movie "Dr. Jekyll and Sister Hyde" (1971).
Clemens was born in Croydon, Surrey. He was related to the American writer Mark Twain (1835–1910). He was married and had two sons.
Clemens died on 10 January 2015 at the age of 83.