Mycroft Holmes is a fictional character appearing in stories written by Sir Arthur Conan Doyle. He is the elder brother (by seven years) of detective Sherlock Holmes. He is described as having abilities of deduction and knowledge exceeding even those of his brother, though their practical use is limited by his poor physique and dislike of fieldwork.

The character has been adapted in various pieces of literature and media, including television series, movies, radio, and comics. He is also popular in culture, being mentioned by many works, which mostly reference his job, personality, or his relationship with Sherlock Holmes.

More Info: en.wikipedia.org