The Classical Calendar: March 16
Valentinian III is assassinated
So Valentinian was assassinated by two Hunnish followers of a rival.
At this point the Roman Empire was struggling to repel the invading Huns. Those opposed to the emperor used this as a tool in order to oust him. in particular one Petronius Maximus, who was probably the one who put the Hunnish assassins up to their task.
He did, however, get his comeuppance, when, having bought the position of emperor, and suddenly realising that he didn’t have the required skills to restabilise the crumbling Empire.
A Roman mob stoned him to death.
Day 72: Valentinian III
Johannes was dead. Valentinian III was secure in his position as emperor of the west, with his mother, Galla Placidia, acting as regent and, naturally, the effective power behind the throne.
Then Aetius arrived with a whole big army of Huns.
Instead of war, however, Aetius and Galla Placidia agreed to negotiate, and in the end, the Huns were paid to go away and Aetius was made general of the Roman army in Gaul. Over the next few years, he fought against the plentiful enemies in Gaul, and his power grew until eventually he controlled all of the armies, making him, not Galla Placidia, the most important power behind Valentinian III.
It is probably all thanks to Aetius that the west did not fall in the early 450s. He turned Attila the Hun away from Gaul in 451 (which has been called the last major military victory of the western Roman empire), and when Attila came back to invade Italy a bit later—there’s actually a hilarious story there involving a rebellious young woman, an engagement ring, and an assumed dowry—Aetius slowed the Hunnic force down with a brilliant (though tactically unwinnable) campaign.
(Attila ended up just ending his invasion and leaving after talking to a few ambassadors sent to convince him to do just that. We don’t really know what happened there.)
By the mid-450s, Aetius had been in effective control of the west for nearly two decades. Valentinian III, long since an adult, and apparently feeling overly secure after the departure of Attila, decided to take power for himself by assassinating Aetius.
He was then killed himself by Aetius’s supporters, so good job there, Valentinian.
The Theodosians (part two)
Constantius III (421, seven months) - Western Emperor. The power behind the throne for most of the 410s, he was co-emperor for seven months with Honorius. He died of natural causes whilst in the middle of working on a military expedition to have his rights recognised by his eastern colleague Theodosius II.
Joannes (423-5) - Western Emperor. A pretender vs. Valentinian III, he was proclaimed emperor at Rome, and had a very shadowy reign. According to Procopius, when captured by the forces of the Eastern empire, first his hand was cut off, and he was then paraded on a donkey in the hippodrome of Aquileia before being beheaded.
Valentinian III (424-455) - Western Emperor. Became emperor in his infancy, ruling under the regency of his mother Galla Placidia, who was fully supported by Theodosius II. He ruled in his own right from 437, but really was under the control of the general Aëtius. During his reign, the Roman empire was raged across by Attila the Hun, something which was only truly ended by Attila’s death and the subsequent power struggle between his sons. After Aëtius’ assassination at Valentinian’s hands (egged on by Petronius Maximus, who we’ll get to soon!), he himself was shortly assassinated by Aëtius’ followers… possibly, again, egged on by Petronius Maximus, who seems to have been a bit of a chess player.
Marcian (450-457) - Eastern Emperor. Of low birth, Marcian was the son of a soldier. He was picked by Theodosius II’s sister, Pulcheria, as her consort, and thus ascended to the purple. He was pretty damn good for the eastern empire, reforming it economically and financially whilst protecting it from external menaces… but at the same time, screwed over the western empire by stopping the payments to Attila that stopped him from waging war (although some have argued he had a large hand in his death). He probably died of gangrene.