Olympias (c. 376 - 316 BC) was the most famous among the seven wives of Philip II of Macedon and the mother of Alexander the Great. She was a princess of Epirus and her marriage to Philip resulted from a political alliance. Their marriage was stormy at best. Olympias took part in a cult of Dionysus whose practices included training and even sleeping with snakes. This reportedly left Philip weary of approaching her room. Meanwhile Philip not only had other wives, he took numerous lovers of both sexes. Something treated as an insult by Olympias.
Philip effectively divorced Olympias in 337 BC and had considered disinheriting their son. Olympias remains among the main suspects when historians consider who orchestrated Philip's murder in 336 BC. Olympias honoring the memory of Pausanias, the assassin directly responsible, for the rest of her life helped establish the suspicion. She was part of the regency left behind by Alexander in Macedon during his campaigns. Ancient sources accuse her of eliminating Cleopatra Eurydice, last and favorite wife of Philip, and at least two of Alexander's half-siblings.
The death of Alexander in 323 left the throne shared by his half-brother Philip III (reportedly retarded) and his infant son Alexander IV. Actually the first was dominated by his wife Eurydice III and the other by his grandmother Olympias. The two women ended up leading Macedon to a civil war. Olympias won by 317 and had both Philip III and Eurydice killed. She was left in control of Macedon.
Cassander, a powerful general and a member of Alexander's successors, led an invasion force from the Peloponnese to Macedon. Olympias was defeated and surrendered in 316 BC. Her only term was her survival. Instead Cassander allowed several enemies of Olympias to take part in her execution. Many were surviving relatives of the various people she had put to death over the years. Cassander would reign as regent for her grandson until taking the throne for himself in 305 BC.