Although the split between the East and West Churches can not easily be put down to one event, the conflict caused in 1054 between Pope Loe IX and the patriarch of Constantinople is often thought, rightly or wrongly, as the key moment. Pope Leo IX sent a delegation to Constantinople to discuss differences which resulted in the excommunication of the patriarch by the delegation and in return the excommunication of the delegation by the patriarch. ^[1]

At Constantinople the Emperor Alexius welcomed Peter's army but there were too many people and no provision had been made for them. There was a general lack of discipline that resulted in repeated attacks and thefts from surrounding villages. Alexius warned Peter to wait for better trained troops to arrive before moving on but the pressure of the army was so great on Constantinople that they were forced to move before help could arrive.

While the People's Crusade led by Peter the Hermit was being crushed in the Holy Land, preparations for the First Crusade carried on in Europe. Those leaders involved were Raymond of Toulouse, Hughes Count of Vermandois, Robert Count of Flanders, Robert Duke of Normandy and Etienne Count of Blois. The leaders arranged to meet at Constantinople and set off taking different routes. Some followed the path across Europe taken by Peter the Hermit, while others took a more southerly routes via the Alps and the Adriatic.

When the crusaders arrived at Constantinople they were greeted by Emperor Alexius. The Emperor was happy for the crusaders to capture areas of the Holy Land but he wanted the land to be under his control. Alexius persuaded the Leaders of the crusaders to swear an oath of allegiance to him and to hand over the land they captured. They could however be allowed to live on and rule that land but not own it.

The crusaders left Regensburg to march across land to Constantinople. ^[2]

Hostilities between the French and German leaders of the Second Crusade became such a problem that the German Emperor, Conrad III, abandoned the crusade and returned to Constantinople. The Second Crusade ended in failure. ^[3]

The Fall of Constantinople came after a seige of some fifty days. ^[4]

A lavish banquet was held at Lille, put on by Philip the Good Duke of Burgundy to raise support for a crusade against the Turks who had captured Constantinople. The banquet was so large that it included a landscape with ships, mock villages, castles and churches. It had a pie in which more than twenty musicians palyed. Chariots of gold were moved around by hidden machinery and a horse had been trained to walk backwards. To complete the spectacle a huge Saracen giant and an elephant appeared. On the elephant rode a female figure meant to represent the Holy Church who appealed to the banqueting guests to join the crusade and save her. ^[5]