As "The Prime Minister of the Underworld" and "one of the most powerful and prominent Mafia bosses in the United States," Frank Costello was known to the authorities. He was known only as "Uncle Frank" to his friends and associates. In this authoritative portrayal of one of the most fascinating people in American criminal history, Pulitzer Prize-winning journalist Anthony M. DeStefano sets out to answer the question of who Frank Costello actually was.