Ptolemy of Numidia was the son of King Juba II of Numidia and Cleopatra Selene II. He was also the grandson of Mark Antony and Cleopatra VII on his mohter's side. He was named in honor of the memory of Cleopatra VII, the birthplace of his mother and the birthplace of her relatives. In choosing her son's name, Cleopatra Selene II created a distinct Greek-Egyptian tone and emphasized her role as the monarch who would continue the Ptolemaic dynasty. She by-passed the ancestral names of her husband. By naming her son Ptolemy instead of a Berber ancestral name, she offers an example rare in ancient history, especially in the case of a son who is the primary male heir, of reaching into the mother's family instead of the father's for a name. This emphasized the idea that his mother was the heiress of the Ptolemies and the leader of a Ptolemaic government in exile.
Through his parents he received Roman citizenship and was actually educated in Rome. Amazingly he grew up in the house of his maternal aunt, and Antony's daughter Antonia Minor, the youngest daughter of Mark Antony and the youngest niece of Augustus. Antonia was also a half-sister of Ptolemy's late mother, also a daughter of Mark Antony. Antonia Minor's mother was Octavia Minor, Mark Antony's fourth wife and the second sister of Octavian (later Augustus). Ptolemy lived in Rome until the age of 21, when he returned to the court of his aging father in Mauretania.
Ptolemy was a co-ruler with his father Juba II until Juba's death and was the last semi-autonomous ruler of Africa. On a visit to Rome in 40 AD he was seen by the Emperor Caligula in an amphitheather wearing a spectacular purpal cloak. A jealous Caligula had him murdered for his fashionable purple cloak.