There are a number of events that can be seen as important in this crusade. The first of these important events is the Council of Clermont. This can be seen as the start of the First Crusade since it was there that Pope Urban II preached the necessity of a crusade.
After Urban called the crusade, many nobles set about recruiting armies. Before they could get that done, however, another important event occurred. This was the People’s Crusade, which was led by Peter the Hermit, a priest. It was composed largely of peasants and minor nobles. It was generally unruly and was prone to attacking those it was not supposed to (like the Byzantines the crusade was supposed to help). It ended up being largely destroyed once it reached Muslim territory.
Another important event in the crusade was also one that was unplanned and not consistent with its mission. This was the set of attacks on Jews in Germany. This was done largely by people who were fired with religious fervor and saw Jews as enemies of Christianity.
Once the “official” crusade got to the Holy Land, it fought four main battles. The first two were the Siege of Nicaea and the Battle of Dorylaeum, both of which occurred in Asia Minor. The third was the Siege of Antioch, which is in the extreme south of Turkey, near to Syria. Finally, there was the Siege of Jerusalem in which the crusaders besieged and took that city.