« Theoi Adelphoi ». Ptolémée II, Arsinoé II et la fondation du mariage endogamique dynastique

This paper analyses the evolving relationship between Ptolemy II and Arsinoe II – brother and sister, but also husband and wife – through documentation dating from their reign. The discussion focuses on the documents that show Arsinoe to be a powerful woman both in her personal life (since she had been queen of Macedonia), and in her status as daughter, sister and wife of kings. The sources show that the theme of dynastic union between brother and sister was clearly highlighted during the joint reign of the Theoi Adelphoi. However, it was only later that this message was fulfilled, first with the ideological and cultic programme of Ptolemy II after 270 BC, and then with the couple Ptolemy III and Berenice II.