15. Ptolemy I’s Successor Kicked Off a Tradition of Incest by Marrying His Sister
The first Ptolemy was a capable general, having learned from and served under one of history’s greatest military geniuses, Alexander the Great. His son and successor, Ptolemy II (308 – 246 BC), did not inherit his father’s military chops, opting instead for peaceful and cultural pursuits such as patronizing scientific research and expanding the Great Library of Alexandria. During his reign, the Ptolemaic court in Alexandria reached a height of splendor that would not be seen again.
Another distinction of the second Ptolemy is that he was nicknamed Phialdelphos (“lover of his sister”), because he took sibling affection to lengths hitherto alien to Greeks and Macedonians, but common among Egyptian royals. He had initially been married to Arsinoe, the daughter of king Lysimachus of Thrace – who was also married to Ptolemy II’s sister Arsinoe II, thus making Lysimachus his father in law as well as brother in law. After Lysimachus’ death, Ptolemy II got rid of the Thracian king’s daughter, Arsinoe, and married his own sister, the widowed Arisinoe II, thus kicking off a tradition of Ptolemaic incest that lasted for centuries, until the dynasty’s fall.