Feng Lang and Feng Miao, believing that Northern Yan is on the verge of destruction in early winter 433, and believing that Princess Murong is planning to have them killed, flee to Liaoxi (in modern Tangshan, Hebei), where Feng Hong had sent their older brother Feng Chong to be the commanding general.

They persuade Feng Chong to surrender to Northern Wei, and Feng Chong sends Feng Miao to Northern Wei to offer his allegiance.

Feng Hong, in response, sends his general Feng Yu to put Liaoxi under siege.

In spring 433, Emperor Taiwu sens his younger brother Tuoba Jian, the Prince of Yongchang, to relieve Liaoxi, and further creates Feng Chong the Prince of Liaoxi with a number of other honors, including ten prefectures as his fief, to try to encourage other defectors.

Tuoba Jian's forces soon surround Feng Yu and force his surrender, then withdraw with three thousand captive households.

Feng Chong now requests permission to go to Helong to persuade Feng Hong to surrender, but Emperor Taiwu does not grant his request.

While Emperor Taiwu has Northern Liang on his mind while also concentrating on Northern Yan, but at the advice of his minister Li Shun, he decides to wait until the death of Northern Liang's long-time prince, Juqu Mengxun.

For the next few years, Emperor Taiwu will launch yearly attacks against Northern Yan with the same pattern, seeking to weaken Northern Yan gradually.

Murong Mugui, with promises of rewards in 433, turns Helian Ding over to Emperor Taiwu, and he has Helian Ding executed.

With the death in this year of Juqu Mengxun, Emperor Taiwu begins to consider conquering Northern Liang but initially continues to accept Juqu Mengxun's son Juqu Mujian as a vassal.

He takes Juqu Mujian's sister as an imperial consort.

The Romans had effectively deserted Pannonia after the German invasion of 395 and the division of the Empire, leaving its largely Illyrian inhabitants to the rule of the occupying Ostrogoths.

After the Romans surrender Pannonia entirely to the Huns in 433, the historical record is silent on Carnuntum, at one time the most important ancient Roman legionary camp of the upper Danube frontier.

Eutyches, archimandrite of a monastery in Constantinople, inclines to Monophysitism.

A vigorous opponent of Nestorianism, he refuses, in 433, to accept the formulary of reunion, signed by John of Antioch and Cyril of Alexandria, that restores unity between the churches of Alexandria and Antioch.

(Theologians of the Antiochene school have emphasized the humanity of Jesus Christ; the Alexandrian school, his deity.)

Aetius enters Italy with a large Hunnic army in 433, and Sebastianus is deposed and flees to Constantinople, seeking refuge at the Eastern court.

Here he obtains the support of influential members of the court; he allows his supporters to start remunerative pirate activities in Hellespont and Propontis.

Aetius gains control over emperor Valentinian III, age fourteen, and becomes his "protector".

Peter (whose title—Chrysologus, “Golden Orator”—will be added to his name at a later date, probably to create a Western counterpart to the Eastern patriarch St. John Chrysostom) becomes archbishop of Ravenna about 433 where, with the aid of Galla Placidia, he promotes the construction of church buildings.

Helian Chang, for reasons not now known, flees Pingcheng and apparently attempts to foment a rebellion in spring 434.

He is killed in battle, and Emperor Taiwu has Helian Chang's brothers put to death.

At the same time, after initially refusing a peace offer from Northern Yan, Emperor Taiwu accepts after Feng Hong offers his daughter as a consort and releases the Northern Wei ambassador Huniuyu Shimen, who had been imprisoned by Feng Hong's brother and predecessor Feng Ba in 414 after being commissioned by Emperor Mingyuan.

Emperor Taiwu, however, orders Feng Hong to also send his crown prince Feng Wangren to Pingcheng to meet him, and Feng Hong refuses, ending the brief peace, and by summer 434, Northern Wei resumes its periodic attacks on Northern Yan.

He again sends Tuoba Jian against Northern Yan, and Tuoba Jian seizes Northern Yan's crops and some of its people before withdrawing.

Meanwhile, around this time, he also takes the sister of the Rouran’s Chilian Khan Yujiulü Wuti as an imperial consort and, to further cement peaceful relations, marries his sister or cousin Princess Xihai to Yujiulü Wuti.

In fall 434, while attacking the Xiongnu rebel Bai Long, Emperor Taiwu, having underestimated the capabilities of Bai's forces, is nearly captured in an ambush; he is saved only by the efforts of his guard Houmochen Jian.

He subsequently defeats Bai and slaughters Bai's tribe.

Aspar, defeated in Africa by the Vandals, is forced to withdraw in 434, in which year he serves as consul.

Justa Grata Honoria, older sister of Valentinian, becomes pregnant from an officer in her household.

The liaison shakes the foundations of the Western Roman Empire.

Circles in the court at Ravenna assume inevitably that Honoria is planning to raise her paramour to imperial rank and challenge her brother.

Valentinian orders his execution.

Vincent of Lérins and the Commonitorium

In 434 CE, the Christian monk Vincent of Lérins (formerly of Auxerre) writes his Commonitorium (Memorandum), a collection of theological notes spanning thirty-three chapters. Wrestling with the complexities of doctrinal development, Vincent seeks to provide a systematic method for distinguishing authentic Christian tradition from heretical innovation.

The Vincentian Canon: A Triple Test for Orthodoxy

In the Commonitorium, Vincent argues that the Church must evaluate doctrine using a threefold test:

1. Ecumenicity – What has been believed by the whole Church.
2. Antiquity – What has been held from the earliest times.
3. Consent – What has been universally accepted by Church authorities.

This principle—summarized as “what has been believed everywhere, always, by all” (quod ubique, quod semper, quod ab omnibus creditum est)—becomes known as the Vincentian Canon. It will remain a foundational criterion for evaluating orthodoxy in both Western and Eastern Christianity for centuries.

Vincent’s Background and Historical Context

Little is known about Vincent’s early life, but he acknowledges having been engaged in secular pursuits, possibly in civil or military service, as implied by his phrase “secularis militia.” Eventually, he joins the monastic community on the island of Lérins, off the coast of southern Gaul, which serves as an important center of theological learning and ascetic practice in the Western Church.

Vincent references the Council of Ephesus, which was held in 431 CE, as having taken place “some three years earlier” (ante triennium ferme). This internal dating places the composition of the Commonitorium in 434 CE.

Influence and Legacy

The Commonitorium becomes one of the most influential theological works of the early medieval Church, shaping Western Christian thought on tradition, heresy, and doctrinal continuity. Though Vincent himself fades into obscurity, his Vincentian Canon remains a cornerstone of Christian theological methodology, invoked by later thinkers in debates on orthodoxy and doctrinal development.