A prelude to The First Crusades, it occurred from April to October, 1096. The campaign was not part of an official Church sanctioned conflict. Started by a religious zealot named Peter The Hermit, he was able to convince French Lord Walter Sans Avoir (and his army of 20,000 men) to join him. In August, many areas of Europe were experiencing severe droughts, famines and plagues. In addition, (and unrelated, but not unnoticed), strange astrological events were happening (eclipses, meteor showers and comets). These all served to cause alarm and would lead to an "end of days" movement.
The Church's call "for redemption only through pilgrimage to Jerusalem", would start many to begin such a journey.
Powerful orator an zealot Peter The Hermit (known for his riding of a donkey everywhere he went), became a rallying point for the peasant masses. He (as others) knew any journeys to The Holy Land would be filled with dangers due to them being under Muslim control. He knew an "army" was needed. His peasant flock would serve. However, many were poor and illiterate. Often hungry and in need, this kind of "army" was dangerous. Luckily for Peter, many nobles also agreed with his opinion of Jerusalem. One was Lord Avoir (who no doubt saw fortune in it), added his considerable military resources to this rabble.
The Army still "grew itself" - recruiting as it went. Avoir's army's arrival at Belgrade (ahead of the peasants), created an incident. The commander of the City garrison refused entry to the visiting army (he had no orders to the contrary). So Avoir's army set about pillaging the countryside for supplies. This an other actions would lead to a massacre of some 4,000 Hungarians. Having engaged "new enemies" and with the "peasant army" now present, Avoir crossed the Sava River. The Crusaders prepared to attack the City of Nis. It was agreed by this City's garrison to provide food and supplies (to get rid of them more quickly). Unfortunately a disagreement between knights and local populace would result in a skirmish. The garrison turned out on the Crusaders. The self-proclaimed "Army of God" lost 10,000.
Now down by a quarter of their starting force, they made their way to Constantinople by August 1. This rabble army of 30,000 was now causing a problem for Byzantine Emperor Alexius I. He told Peter and his army to stay put and wait for Avoir (afraid that Peter's army would annoy the Turks so much that they would slaughter them). With Avoir and additional French and German reinforcements, they set off again - over the Bosphorus (again courtesy of Emperor Alexius).
The French pillaged the suburbs of Nicaea for supplies and the Germans marched on Xerigordon. The Turks had enough. They dispatched a large army to retake it. The siege of the City was so large and heated (and the Germans were low on supplies). So much so that they had to drink donkey and horse blood and well as their own urine. They surrendered to the Turks (many converted to Islam or death!).
News of the "taking" of Xerigordon (news of it's fall had not reached Peter yet), cause his peasant army to spur forward (they wanted their share of treasure as well). Half way there, Peter went back to Constantinople for supplies (or maybe he received OTHER news). The Crusader knights with him thought it too "cowardly" to wait around, and continued on. On October 21, an army of 20,000 moved on Nicaea. Three miles out, the Turks waited in ambush. Most of the Crusaders fell in battle. Anyone who surrendered (and converted) were spared. Some 3,000 were left. With Byzantine assistance, they would return to Peter at Constantinople. The stage was now set for The First Crusade of 1096!