The First Crusade (1096-1099 C.E.) was the most successful. The Second (1147-1148 C.E.), Third (1189-1193 C.E.), Fourth (1201-1204 C.E.) and Last (which came soon after the Fourth) Crusades were less successful and added to the tension between the Christians and Muslims in what is now the Middle East.
The Crusades were military expeditions executed to seize Holy Lands from Muslim control. During the First Crusade the Holy Lands and Jerusalem were seized in 1099 C.E. Another consequence of the First Crusade was the establishment of Christian settlements along the eastern Mediterranean coast. The settlements survived for approximately one hundred years.