Overview
Olympias (; c. 375–316 BC) was a Greek princess of the Molossians, and the eldest daughter of king Neoptolemus I of Epirus, the sister of Alexander I of Epirus, the fourth wife of Philip II, the king of Macedonia and the mother of Alexander the Great. She was extremely influential in Alexander's life and was recognized as de facto leader of Macedon during Alexander's conquests. After her son's death, she fought on behalf of Alexander's son Alexander IV, successfully defeating Adea Eurydice. After she was finally defeated by Cassander, his armies refused to execute her, and he finally had to summon family members of those Olympias had previously killed to end her life. According to the 1st century AD biographer, Plutarch, she was a devout member of the orgiastic snake-worshiping cult of Dionysus, and he suggests that she slept with snakes in her bed.
Origin
Olympias was the eldest daughter of Neoptolemus I, king of the Molossians, an ancient Greek tribe in Epirus, and sister of Alexander I of Epirus. Her family belonged to the Aeacidae, a well-respected family of Epirus, which claimed descent from Neoptolemus, son of Achilles. Apparently, she was originally named Polyxena, as Plutarch mentions in his work Moralia, and changed her name to Myrtale prior to her marriage to Philip II of Macedon as part of her initiation into an unknown mystery cult.
The name Olympias was the third of four names by which she was known. She probably took it as a recognition of Philip's victory in the Olympic Games of 356 BC, the news of which coincided with Alexander's birth (Plut. Alexander 3.8). She was finally named Stratonice, which was probably an epithet attached to Olympias following her victory over Eurydice in 317 BC.
Queen of Macedonia
When Neoptolemus I died in 360 BC, his brother Arybbas succeeded him on the Molossian throne. In 358 BC, Arybbas made a treaty with the new king of Macedonia, Philip II, and the Molossians became allies of the Macedonians. The alliance was cemented with a diplomatic marriage between Arybbas' niece, Olympias, and Philip in 357 BC. It made Olympias the queen consort of Macedonia, and Philip the king. Philip had allegedly fallen in love with Olympias when both were initiated into the mysteries of Cabeiri at the Sanctuary of the Great Gods, on the island of Samothrace, though their marriage was largely political in nature.
From Wikipedia (CC BY-SA 4.0).