Valentinian III came to power when he was only six years old (425). His ascension to the throne was contributed to by the armed forces of his cousin Theodosius II – the emperor of the Eastern Empire, thus proving the importance of blood ties, which connected both, only recently separated by their common grandfather, Emperor Theodosius I, halves of the Roman Empire. The alliance between the rulers was sealed by the marriage of Valentinian III with the daughter of Theodosius II – Licinia Eudoxia. The emperor was then eighteen years old, while his wife fifteen. Until that time Galla Placidia cared for both her son and the empire. Her significance as well as influence however, gradually lessened, while real power in the empire passed on to Aetius – an army general, an outstanding strategist, and an above-average politician. He was the one who held all authority, the army was devoted to him, while his enemies respected him, and it was he who truly personified the empire and all the values connected with it. The Huns with Attila, with whom Aetius initially allied against the Visigoths, but later fought against, constituted a real threat and danger, thus his position was unchallenged. At the moment of the downfall of their power (453), the general no longer seemed irreplaceable, or at least that is what the emperor thought, desiring to finally come out of his shadow, since he had been limited to the presentation of the imperial majesty.

The main residence of the emperor, was at that time located in the safe confines of Ravenna, however as the first after Emperor Maxentius, Valentinian III often resided in the Eternal City. He took part in the meetings of the Senate, church ceremonies and meetings with the then bishop of Rome – the charismatic Leo I. During his pontificate the city had changed its appearance. Pagan temples were empty, while pilgrims walked the streets, attracted by the visions of visiting holy places, especially those connected with two apostles – St. Peter and St. Paul, making the city increasingly famous. Deaconates, monasteries, hostels, and hospices for pilgrims sprung up in place of pagan buildings of Rome, which had desires on becoming the most important center of the Christian world. Pope Leo I strove with all his heart to make it into a holy city (urbus sacra), the first among all the other bishoprics. He, as the head of the Church, received from Valentinian III, the right to hold jurisdiction over all bishops of the Western Empire. The imperial couple did not forget to grant the Church with valuable foundations. Along with Licinia Eudoxia, Valentinian supported the construction of the Church of San Pietro in Vincoli, contributed to the reconstruction of the Basilica of St. Paul Outside the Walls (San Paolo fuori le mura) after a fire, was the founder of a chapel by the Church of Santa Croce, and also donated valuable silver and gold ornaments for the decoration of the Basilica of Santa Maria Maggiore.

Most likely the emperor dreamed of restoring the proper rank to the imperial scarlet, of obtaining the respect of the army and making independent decisions. For years he held a grudge against Aetius and it did not simply concern his own, multiple-years long position of a puppet ruler, as he himself felt and of which his surroundings constantly reminded him. What was the direct cause for the shameful act, which he decided to commit, we do not know. Perhaps it was the fact that Aetius rejected his imperial plans, at the time, when he came within a hair’s length of acquiring the crown of the Eastern Empire after the death of Theodosius II. He had every right to pursue it, but Aetius was a staunch opponent of such a step. Another reason for the emperor’s discontent was the general’s plans, which although beneficial for the state, were not accepted by the already threatened in his meagre authority Velentinian. Without a male heir, he had to think of a successor to the throne, while Aetius’s proposal to marry off his son Gaudentius to the emperor’s daughter solved this very problem Why then, did this Christian ruler have to resort to murder to get rid of his rival? His calculation was rather simple – any other method brought with it the threat of a civil war and revolt of the army.

The unfortunate incident took place in the year 454 in the imperial palace on Palatine Hill and was described in detail by the chronicler Priscus. During Aetius’s report about the state of the finances and income from taxes, Valentinian stood up from his throne shouting that he has had enough betrayals and lunged at the surprised general with his sword drawn. He was aided by a eunuch – the imperial primicerius and the so-called administrator of the imperial sleeping chambers Heraclius, who completed the work of his master. The battered corpse of Aetius was set out on the Forum Romanum. The expected military revolt did not come to fruition and the emperor could breathe a sigh of relief – after psychological imprisonment he finally became the master of his own decisions and deeds, ready for the challenges, which fate would put in front of him. As it would turn out not for very long, since a few short months later he would also fall victim to assassins. Historians cannot agree, what drove them. The two sent by Senator Petronius Maximus Goci – former soldiers of Aetius and officers of the imperial guard – murdered Valentinian with strikes to the head, while he was practicing archery not far from Rome. The killers, collecting the imperial diadem and horse, then went to Petronius Maximus, who one day later put on the imperial scarlet and showed up in the imperial palace on Palatine Hill. In order to put to rest any doubts, he immediately married the widow of the murdered emperor – Licinia Eudoxia. His fate was even more cruel though – he was torn apart by Roman rabble, blaming him for brining Vandals into Rome with Genseric at the head, in revenge for the emperor’s death. His limbs were quartered and first displayed for everyone to see and later thrown into the Tiber.