Alexander the Great was, well, great (there was very little tendency towards sarcastic monikers in ancient times). By the time he died, he was the proclaimed king of Asia, with a kingdom which stretched from Greece and Egypt to modern India--comprising one of the largest and most culturally diverse empires the world has ever seen. Intelligent, courageous and a leader of men; Alexander the Great was a man's man.
He was also a momma's boy. You may already be tangentially aware of the existence of Alexander's mother thanks to the frighteningly incest prone depiction of Olympias by Angelina Jolie. Never has an audience been given so much reason to forgive an Oedipus Complex than the movie Alexander.
Beautiful, powerful and heavily involved in a snake-worshiping cult of Dionysus, Olympias is regularly depicted as sleeping with snakes. Heck, Olympias was the Angelina Jolie of 4th century B.C.
When questions came up about Alexander's claim to the throne, she claimed that the god Zeus himself impregnated her under an oak tree, a legitimate claim to any throne, obviously. However knowing what we do of Olympias, that is strangely plausible.
When her husband, Phillip, took a new wife and divorced Olympias, she had him assassinated. Well, we don't know for sure she was behind it, but let's just say she is said to have placed a golden crown on the murderer, dedicated a memorial to him and hung the sword he used to kill Phillip in a temple of Apollo, elevating it to the status of a legendary weapon. She then forced her replacement wife to hang herself and had the two children she had with Phillip killed, assuring Alexander's claim to the throne was unrivaled. She didn’t mess around.
When the now-king Alexander was gone (read: the entire time he was king), Olympias wielded great influence and power, often contradicting the efforts of the guy who was supposed to do that, the regent Antipater. Antipater's many official complaints on the matter went unnoticed by Alexander, who was happy to let his mother do as she wished.
After Alexander's death, Olympias remained a prominent world figure, waging wars on behalf of her grandson's failed claim to the throne. Most telling is the last message from Antipater to his beloved Macedonian people. On his deathbed, with Olympias eager for the opportunity his vacant seat would provide, Antipater coughed out a warning to the Macedonians to never let a woman rule over them. Not a super attractive one, anyway.