Agrippina the Younger

Sister of Caligula, niece and fourth wife of Claudius, mother of Nero. The most politically active woman of the Julio-Claudian house, she persuaded Claudius to adopt her son Nero over his own son Britannicus and is widely believed to have poisoned Claudius once Nero was secure as heir. Nero, having tired of her tutelage, had her murdered after a botched assassination by collapsing-ship.