Mycroft Holmes

Mycroft Holmes was the brother of Sherlock Holmes and an ally of Bernice Summerfield. (BFBS: The Adventure of the Diogenes Damsel)

Biography
The Seventh Doctor, Ace and Benny met Mycroft while he was under the employ of the British government. (NA: All-Consuming Fire)

In 1882, Mycroft visited Sherlock to inform him that their father had died and reminded Sherlock that he had a duty to their sister. He persuaded Sherlock to travel with him back to Yorkshire. (FP: Erasing Sherlock)

In 1916, Mycroft was working for the British government during World War I. (OBIW: The Found World)