Emperor Mingyuan's wife Consort Yao had died in 420, and he posthumously honored her as an empress.

The Emperor suffers a major illness in 422, apparently caused by medicines that alchemists had given him that were supposedly capable of extending life spans.

He consults Cui Hao on what he should do to prepare for events after his death.

Cui Hao predicts that he will recover, but advises him to create his oldest son, fourteen-year-old Tuoba Tao, the Prince of Taiping, crown prince, then transfer some of the authorities to the crown prince so that his own burdens could be lessened.

Baba Song also agrees, and Emperor Mingyuan creates Tuoba Tao crown prince, and further has Crown Prince Tao take the throne to serve as the secondary emperor.

He commissions his key advisors Baba, Cui, Daxi Jin, Anchi Tong, Qiumuling Guan, and Qiudun Dui to serve as the Crown Prince's advisor.

From this point, Crown Prince Ta rules on most matters, particularly domestic matters, while Emperor Mingyuan himself only rules on important matters.

Later in 422, after hearing about the death of Liu Yu (who had seized the Jin throne in 420 and established Liu Song), Emperor Mingyuan breaks off relations with Liu Song and calls his council, informing the advisors that he plans to attack and seize three major cities south of the Yellow River from Liu Song—Luoyang, Hulao, and Huatai, despite Cui's opposition.

He commissions Daxi as the commander of the forced to attack Liu Song.

Daxi first puts Huatai under siege, but after he is unable to capture it quickly, Emperor Mingyuan personally led an army south to aid Daxi.

He also has Crown Prince Tao lead an army to the northern border, to guard against a Rouran attack.

Huatai then falls.

The emperor has, however, inspired his generals to repel the Persian invasions of 421 and 422.

He issues a law on March 3 to form provisions in peacetime.

He instructs landowners leasing towers in the Theodosian Walls to assist with the buildup of emergency goods.

The emperor pays a annual tribute of three hundred and fifty pounds of gold to the Huns in order to buy peace.

Theodosius II receives a statue at Hebdomon, a military parade ground on the shores of the Propontis, just outside Constantinople.

On its base (fragments are now in the Istanbul Archaeology Museum), an inscription praises him as “everywhere and forever victorious.”

The Roman-Sassanid War escalates as Theodosius transfers further troops to the East, while Bahram personally takes the field, supported by a large contingent of Lakhmid Arabs, and drives the Romans from Nisibis.

Mundhir marches into Roman territory and ravages imperial lands as far as Antioch, where he is routed by Vitianus.

While Al-Mundhir’s troops are crossing the Euphrates on their return, many of his forces drown.

Syriac sources give a figure of those who drowned at seventy thousand while Socrates give a higher figure of one hundred thousand.

Bahram agrees to tolerate Christianity throughout the Persian empire under the one hundred-year peace concluded in 422 between Ctesiphon and Constantinople; the Romans reciprocate by agreeing to tolerate Zoroastrianism throughout the Roman empire.

The Hepthalites, or White Huns, move south from the Altai Mountains region into Transoxiana, Bactria, Khorasan and eastern Persia, displacing the Scythians before 425.

The walls of Rome's Flavian Amphitheater (the Colosseum) crack during an earthquake.

Not much is known of the Frankish king Theudemeres.

A war broke out between the Franks and the Romans according to Gregory of Tours some unknown time after the fall of the usurping Emperor Jovinus (411-413) who had been supported by the Franks.

A Roman army in about 422 enters Gaul.

King Theudemeres and his mother Ascyla are executed by the sword.

Theudemeres' reign is supposed to be before that of king Chlodio, and the Chronicle of Fredegar makes Chlodio his son.

Theudemeres must have been a cousin of Arbogastes.

Emperor Mingyuan also starts a major building project in 423—the building of a wall on the northern borders to defend against Rouran attacks.

Emperor Mingyuan dies in winter 423, and Crown Prince Tao takes the throne as Emperor Taiwu.