To get the ball rolling, I present one of my historical foes: Cassander - a snake amongst the godly.
The death of Alexander the Great in 323 BC [co-incidentally the same year that Cassander turned up to Alexander’s court in Babylon…] left Cassander’s father, Antipater, as regent of Alexanders vast empire. Antipater fought across the empire to secure the succession of Alexander’s son, Alexander IV.
When the succession was secure, he returned to Macedon and soon after fell ill and died. Antipater did not make Cassander his successor to the regency, but instead passed the duty to Alexander’s trusted [and aged] companion Polyperchon. Cassander didn’t think much of this ‘snub’ [although why would the regency be passed to him?] and rallied Alexander’s other Diadochi [those who controlled or attempted to control Alexander’s empire after his death] to support him.
In securing his own succession, Cassander killed: Alexander’s son and heir to his empire, Alexander IV, Alexander’s mother, Olympias, his widow Roxanne, and his suspected bastard Heracles.
Cassander crowned himself king of his own little patch of Alexander’s great work on the bodies of it’s true successors. The bodies of women and children appear to be poor foundations for an empire, at least for Cassander’s Antipatrid dynasty. It was succeeded by the Antigonid dynasty not long after Cassander died.
For those of us who adore Alexander the Great, there cannot be many people more hated than Cassander.