Daughter of the Crocodile (Ptolemies Quartet)

the long version

Pleasure-loving Ptolemy II marries his reptilian sister, Arsinoe Beta, who promises to win his wars for him. Worthy Ptolemy III avenges the murder of his sister by conquering the Syrian empire . . . and marries a murderess. Ptolemy IV prefers drinking and dancing to government, maltreats his sister-wife, and lets power slip into the hands of his vicious minions, Agathokles and Agathokleia of Samos. Chaos reigns, leaving Egypt to be ruled by the six-year-old Ptolemy V - who will marry the first of the Kleopatras.