Agrippina the Younger

Lived: 15-59 CE Where: Roman Empire

When it comes to kingmakers of the Roman Empire, your first thought might be of the Praetorian guard, who assassinated Emperor Caligula and replaced him with his uncle, Claudius. Still, for this list we’re going to make the case for Agrippina, Claudius’s niece and fourth wife, who held a lot of power during his reign. After marrying Claudius and becoming empress, Agrippina persuaded her husband to adopt her son from her first marriage, Lucius, who subsequently took the name Nero. She worked to prevent Claudius from naming his son Britannicus as his heir, wanting him to choose Nero instead, and she even executed Britannicus’s tutor, who confronted her for her devious plot. Claudius later regretted his decision to choose Nero over Britannicus and he began to favour his son again before his sudden death in 54 CE – as ancient chroniclers would have us believe, he was poisoned by Agrippina.

After Claudius’s death, Agrippina became de facto ruler of the empire and sole influence over her son at the start of his reign, as the young emperor was only 16 years old, and she murdered the political rivals who opposed her. However, her relationship with Nero soured and her influence over him weakened, with Agrippina threatening to turn her support over to Britannicus and make him emperor. In retaliation, Nero poisoned Britannicus and Agrippina was eventually exiled, before she was murdered on her son’s orders in 59 CE.