Eastern Wei sends an advance guard of three army columns through the Tong Pass to attack Western Wei.

The Western army under Yuwen Tai defeats one of the columns while the others retreat.

Yuwen follows up, but runs into the main Eastern army (two hundred thousand men).

The Westerners are pushed back through the pass and the Eastern army emerges from the mountains.

Unexpectedly, they are charged in the flank by ten thousand Western cavalry: six thousand Easterners are killed and seventy thousand captured.

Justinian issues an edict in 537 depriving his Jewish subjects of civil equality and religious freedom.

Decreeing that Jews must maintain (pay for) municipal government, even though they are forbidden to hold office, he also censors part of the synagogue liturgy for being anti-trinitarian.

The Justinian Code has established the More Judaico, or Jewish Oath, based on the notion that no heretic could be believed in court against a Christian.

Various methods are used to ensure that the Jew would deliver truthful testimony.

These include swearing on an opened Torah scroll while standing on a pigskin or while wearing a belt of thorns, or even standing on a stool wearing a “Jews hat.” The Codex Justinianeus (Corpus Juris Civilis) unites church and state, effectively making a non-citizen of anyone not connected to the Christian church.

A certain John Cottistis starts a short-lived rebellion against Justinian I and is declared emperor at Dara, but is killed by conspiring soldiers four days later.

The annexation of Provence is completed, with Chlothar's help, in the winter of 536–537.

Chlothar receives the cities of Orange, …

…Carpentras, and …

…Gap.

Vitiges gathers together an army of forty-five thousand men and on March 2 initiates a siege of Rome, subjecting the city to privation and starvation.

Belisarius conducts a delaying action outside the Flaminian Gate, where he and a detachment of his bucellarii are almost cut off.

Vitiges sets up seven camps, overlooking the main gates and access routes to the city, in order to starve it out.

He blocks the Roman aqueducts that are supplying Rome with water, necessary both for drinking and for operating the corn mills.

Vitiges attempts to assault the northern and eastern city walls with four siege towers on March 21, but is repulsed at the Praenestine Gate, known as the Vivarium, by the defenders under the imperial generals Bessas and Peranius.

Vigilius gives Belisarius the letters from the Court of Constantinople, which recommend Vigilius himself for the Papal See.

False accusations—namely, that Pope Silverius had written to Vitiges offering to betray the city—now lead Belisarius to depose Silverius on a charge of treasonable correspondence with the Goths, and degrade him to the rank of a simple monk.

In his place, Vigilius is elected pope, consecrated and enthroned on March 29, 537.

Silverius finds his way to Constantinople, where Justinian entertains his complaint and sends him back to Rome, but Vigilius will eventually be able to banish his rival to the prison island Pandataria (Ventotene), where Silverius will spend the rest of his life in obscurity.

The Ostrogoths besieging Rome, among other acts of sabotage, destroy the five hundred-year-old Aqua Virgo aqueduct, putting an end to the three-centuries-old Baths of Caracalla, then try to use the underground channel as a secret route to invade the city.

Belisarius receives his promised reinforcements, sixteen hundred cavalry, mostly of Hunnic or Slavic origin and expert bowmen, on April 9.

Despite shortages, he begins raids against the Gothic camps and Vitiges is forced into a stalemate.

The Goths capture the Portus Claudii at Ostia, left unguarded by the Romans, in April.

Belisarius, forced to unload his supplies at Antium (modern Anzio), sends urgent messages for reinforcements to Constantinople.