According to John of Antioch, Maximus was acutely aware that while Aëtius was alive he could not exact vengeance on Valentinian, so Aëtius had to be removed. He therefore allied himself with a eunuch of Valentinian's, the "primicerius sacri cubiculi" Heraclius, who had long opposed the general, with the hope of exercising more power over the emperor. The two of them convinced Valentinian that Aëtius was planning to assassinate him and urged him to kill his "magister militum" during a meeting, which Valentinian did with his own hands, with the help of Heraclius, on 21 September 454.