Ptolemy Caesar

Ptolemy Philopator Philometor Caesar, better known as Caesarion, was the son of Pharaoh Cleopatra VII. (PROSE: State of Change, The Last Pharaoh, The Ruby's Curse)

Biography
Caesarion was born in Egypt, however he and his mother soon moved to Rome with his father Julius Caesar. There, he and his motherlived in one of Caesar's houses on the banks of the River Tiber. (PROSE: The Ruby's Curse)

Caesarion had three younger half-siblings by his mother and Mark Antony. (PROSE: The Last Pharaoh)

On 15 March 44 BC, Caesarion, aged three, fled with his mother from Rome to Alexandria following the death of his father. River Song met the pair of them just prior to their departure. (PROSE: The Ruby's Curse)

According to history, a year after his mother's suicide in 30 BC he was murdered by Octavian. However, in Berenice he was met by 52nd century archaeologist Ventrian, who he believed was a god disguised as a beggar. Ventrian used the device known as the Eye of Horus to place Caesarion into River Song's new manuscript The Ruby's Curse, where he existed as Phil, the sidekick of Melody Malone. Later, River Song used the Eye of Horus to re-unite Caesarion with his mother and siblings somewhere where they would not be found. (PROSE: The Last Pharaoh, The Ruby's Curse)

Alternate timeline
The alternate Rome Terra Nova, created by the Rani using the power of Iam, was home to an alternative Caesarion, the son of Mark Antony and Cleopatra VII. After the Sixth Doctor managed to move Terra Nova to a new solar system, allowing it to continue existing in the universe separate from the normal Earth, this Ptolemy Caesar became its peaceful ruler. (PROSE: State of Change)