Arsinoe II was the daughter of Ptolemy I, one of the generals of Alexander the Great who became the ruler of Egypt after the death of the Macedonian king, and his wife, Berenice I. Arsinoe was one of three children born to the couple, including her future husband, Ptolemy II.
We know relatively little of Arsinoe’s early years. Though she may have been born in Memphis, she was raised in her father’s new capital of Alexandria. Based on her later patronage of scholars, it is thought that her education had been as wide-ranging as that of her brothers.
At fifteen, Arsinoe married the sixty-year-old Lysimachus, King of Thrace, Asia Minor and Macedon. The pair had three children: Ptolemy, Lysimachus, and Philip. King Lysimachus had a son from his previous marriage, Agathocles, who was executed for treason.
Some sources identify Arsinoe as the cause of his execution, citing her desire to see her sons succeed their father. It is unclear whether that was the case. After Lysimachus’s death, Arsinoe married her paternal half-brother, Ptolemy Ceranus. It was an unhappy political match.
Fearing Ptolemy Ceranus’s power, Arsinoe conspired against him with her sons. This was a fatal mistake that saw Lysimachus and Philip killed by her husband. Sometime after their deaths, Arsinoe fled to Egypt to seek the protection of her brother, Ptolemy II.
The marriage of Ptolemy II and Arsinoe II was the first full-sibling marriage of the dynasty, and it would not be the last. The pair were given the epithet ‘Philadelphos’ which meant ‘sibling-lovers’ and the match was met with disquiet from their subjects.
Arsinoe became a co-ruler of Egypt alongside her brother. She appeared on coins with him and took part in the rituals and display of the Ptolemaic court. Her rulership would be the pattern followed by many subsequent Egyptian queens.
After her death, Ptolemy II established the cult of Arsinoe Philadelphus and she proved popular with both the Greeks and Egyptians throughout the Ptolemaic period.
Elizabeth Donnelly Carney, Arsinoe of Egypt and Macedon: A Royal Life (Oxford: Oxford University Press, 2013)
Sheila L. Ager, “The Power of Excess: Royal Incest and the Ptolemaic Dynasty,” Anthropologica 48 (2006): 165-186.