Ptolemy I (c. 367–283 BC)

Ruler of Egypt from 323 BC, king from 304 BC. One of Alexander the Great's most valued generals, he was given Egypt as his share of Alexander's conquests. His capital, Alexandria, became a centre of trade and learning; here, the mathematician Euclid worked under his patronage, and construction of the great library and museum began. Ptolemy's rule established a dynasty of Macedonian kings that governed Egypt until 30 BC.

Ptolemy had to fight off several challenges to his reign, but eventually extended his rule to Palestine, Cyprus, and the Aegean. His nickname was earned after he successfully defeated a siege of the island of Rhodes by the general Demetrius, in 304.