Danny, as he is affectionately called by his family, grows up in a poor neighborhood in the Bronx. He idolizes his brother, James. His father is a bootlegger, and they become rich working with Vito Corleone. By the early 1950s, he becomes the assistant Attorney General in New York. He and his brother are both womanizers.
By 1956, his father makes a deal with Corleone family consigliereTom Hagen to get his son, James, elected president. Danny works on his brother's campaign and in 1960, he becomes Attorney General after James is elected president.
In 1964, his brother is assassinated and Danny realizes who was behind it. He steps down as Attorney General and runs for governor of New Jersey in 1966. He runs for president in 1968, but is assassinated in a manner similar to his brother.