Fourth Crusade
The Crusaders Assemble
The first Crusader army formed in a gallant, chivalric manner, as a by-product of a tournament help in Champagne in November 1199. The count of that land, Theobald, hosted a grand event that was attended by knights from all over northern France. As part of the festivities, Count 
Theobald and Count Louis of Blois took the cross. Champagne and Blois both had a long crusading tradition, and the preachers had been active in northern France, so they were likely inspired to exert their leadership. As word spread of their deed, other lords likewise too the cross: Count Baldwin of Flanders, Theobald's brother-in-law; Count Hugh of St. Pol, Counts Geoffrey and Stephen of Perche, and many others besides. Theobald's older brother, Henry, had participated in the Third Crusade and had become the King of Jerusalem, so Theobald had very close ties with the Holy Land.
Before the Crusade ever left, however, Count Theobald died (May 1201). The Crusaders then chose Boniface of Montferrat (a marquisate in northwestern Italy) as their leader. Boniface, too, had close ties wtih the Holy Land. He was descended from crusaders. His oldest brother (now dead) was the father of King Baldwin V of Jerusalem. Another brother was the same Conrad of Montferrat who had saved Tyre from Saladin and who had been assassinated in 1192. Boniface brought in yet another Byzantine tie, as well. Another of his brothers, Renier, had married a daughter of Manuel Comnenus. Although he was killed in 1183, Renier may have been given rulership over Thessalonica by Emperor Manuel, and Boniface may have from the beginning had his eye on recovering what he regarded as a family estate. One other connection was made with Boniface: he was a close friend to Philip of Swabia, who was married to Irene, the deposed Isaac Angelus' sister. So, Boniface brought to the leadership of the Crusade an interest in championing the cause of Isaac against Alexius III.
The Crusaders assembled first at Soissons, then moved south to Cîteaux in September, where they were joined by a large number of Burgundians. They then moved on to Italy, not in a single organized army, but in separate parties, trickling in to Venice over the course of that summer, thereby delaying the agreed departure date. Moreover, a number of leaders decided to set sail from Marseilles rather than from Venice. The number of soldiers who actually made it to Venice was far less than had been originally estimated.
The result was that by autumn of 1201, the Crusaders were late and were behind in their payments, for those who did show up could not possibly pay the fee that had been set for a much larger army. The original agreement had calculated 33,500 men, whereas perhaps only 11,000 or so actually showed up in Venice. The Crusaders had assembled, but Venice was not about to transport them until it had received the amount stipulated in the contract. Crusades were crusades, but business was business.