Genealogy researchers with Ancestry.com discovered that Cumberbatch and Sir Arthur Conan Doyle are 16th cousins, twice removed. Doyle died in 1930, and Cumberbatch currently plays his most famous character on the PBS television series. Their common ancestor is John of Gaunt from the 14th century, who was the duke of Lancaster and the fourth son of King Edward III of England. He’s Doyle’s 15th great-grandfather and Cumberbatch’s 17th great-grandfather.
A relation to Conan Doyle is cool; John of Gaunt is really cool.