After his pivotal victory at Issus in 333 BCE, Alexander the Great swept south to capture Egypt, exploiting its wealth to finance his assault on the Persian Empire. After several months, Alexander left to campaign eastward, appointing Cleomenes as his governor in Egypt. On Alexander’s death in 323 BCE, the first Ptolemy was originally the governor selected by Perdiccas, Alexander’s successor: however, as the empire rapidly dissolved, he made a bid for independence. Over the next two decades, Ptolemy emerged secure from the Wars of the Diadochi between Alexander’s generals, assuming the title of Pharaoh in 305 BCE. He proved an able ruler – he and his son Ptolemy II extended their dominion over the Eastern Mediterranean, and southward to Aswan and the Red Sea. Ptolemy II in particular was a great patron of learning: Alexandria acquired the largest library in the world; commerce and agriculture prospered. Thereafter, the dynasty dramatically degenerated in a welter of intrigue, inbreeding and infanticide.