Ptolemy I Soter (Greek: Πτολεμαΐος Σωτήρ, Ptolemaios Soter, i.e. Ptolemy the Savior, 367 BC – 283 BC) was a Macedonian general under Alexander the Great who became ruler of Egypt.
His mother was Arsinoë of Macedonia; his father is unknown. He was described in ancient times as the son of Lagus, a Macedonian nobleman, but there are also suggestions that he was illegitimate, and even that he was the son of Philip II of Macedon (which would make him the half-brother of Alexander the Great if true).
Ptolemy was one of Alexander the Great’s most trusted generals, and among the seven somatophylakes, or bodyguards, attached to his person. He was a few years older than Alexander, and his intimate friend since childhood. He may even have been in the group of noble teenagers tutored by Aristotle. He was with Alexander from his first campaigns, and played a principal part in the later campaigns in Afghanistan and India. At the Susa marriage festival in 324, Alexander had him marry the Persian princess Artakama. Ptolemy’s consort was Thaïs, the famous Athenian hetaera and one of Alexander’s companions in his conquest of the ancient world, who contributed somewhat to my character of Artemis.
Ptolemy made himself ruler of Egypt after Alexander’s death in 323 BC. Unlike many of the other Diadochi, he proved an able administrator with a vision that was larger than mere conquest and domination. It was his efforts that made Alexandria the greatest city in the Hellenistic world and he might be said to have done more to create the Hellenistic age than Alexander. He certainly left a more lasting impression on the world, both as ruler of Egypt (323 BC – 283 BC) and founder of both the Ptolemaic Kingdom and the Ptolemaic Dynasty. In 305/4 BC he took the title of king.