Mark Gatiss is a British actor, writer, and producer, best known for his work on television. He gained fame as a co-creator and writer of the critically acclaimed series Sherlock, where he also played the character Mycroft Holmes. Gatiss has been involved in various other projects, including the horror series Inside No. 9 and the historical drama Doctor Who. In addition to his television work, Gatiss has appeared in films and stage productions. He is known for his contributions to the BBC and has a strong interest in Victorian literature and horror, often incorporating these themes into his writing and performances.