Who is Marc-Ange Draco (The Capu) from On Her Majesty's Secret Service and what is their importance?

Draco is the Capu, or head of the Union Corse, the French mafia. He is also Tracy's father. Bond and Draco become instant friends when they first meet, although Draco has Bond brought to him by force. Draco partners with Bond to destroy Blofeld's operation on Piz Gloria.