In 1095, after the head of the Roman Catholic Church Pope Urban II started to urge faithful Christians to undertake an armed pilgrimage to Jerusalem, the People's Crusade was conducted for roughly six months from April to October 1096.

The peasant army of this crusade was destroyed by the forces of the Seljuk Turks under Kilij Arslan at the Battle of Civetot in northwestern Anatolia.

Spurring them on had been a number of meteorological occurrences beginning in 1095 that seemed to be a divine blessing for the movement: a meteor shower, aurorae, a lunar eclipse, and a comet, among other events.

He claimed to have been appointed to preach by Christ himself (and supposedly had a divine letter to prove it), and it is likely that some of his followers thought he, not Urban, was the true originator of the crusading idea.

[a] In the late spring and summer of 1096, crusaders destroyed most of the Jewish communities along the Rhine in a series of unprecedentedly large pogroms in France and Germany in which thousands of Jews were massacred, driven to suicide, or forced to convert to Christianity.

[13][12][10][14] Estimates of the number of Jewish men, women, and children murdered or driven to suicide by crusaders vary, ranging from 2,000 to 12,000.

[16] Edward H. Flannery's estimate is that 10,000 were murdered over the longer January-to-July period, "probably one-fourth to one-third of the Jewish population of Germany and Northern France at that time.

This resulted in skirmishes with the Belgrade garrison and, to make matters worse, sixteen of Walter's men had tried to rob a market in Zemun across the river in Hungary and were stripped of their armor and clothing, which was hung from the castle walls.

However, a few Germans got into a dispute with some locals along the road and set fire to a mill, which escalated out of Peter's control until Niš sent out its entire garrison against the crusaders.

[21] Peter was rejoined by the French under Walter Sans Avoir and a number of bands of Italian crusaders who had arrived at the same time.

Once in Asia Minor, they began to pillage towns and villages until they reached Nicomedia, where an argument broke out between the Germans and Italians on one side and the French on the other.

[22] Back at the main crusaders' camp, two Turkish spies had spread rumors that the Germans who had taken Xerigordos had also taken Nicaea, which caused excitement to get there as soon as possible to share in the looting.

His will prevailed and, on the morning of 21 October, the entire army of 20,000 marched out toward Nicaea, leaving women, children, the old and the sick behind at the camp.

Eventually the Byzantines under Constantine Katakalon sailed over and raised the siege; these few thousand returned to Constantinople, the only survivors of the People's Crusade.