The Crusades failed for a number of reasons: First,There was the incapability of eastern and western Europe working together. This was precipitated largely because of the great rift between the Western Roman church and the Eastern Orthodox or Greek Church. Consequently, the Western church had to go it alone with little or no assistance from Constantinople. Second, the Crusades also lacked the sea power needed. They were forced to go a long overland route from Germany or France through Eastern Europe and Asia minor.The complete exhaustion that this trip entailed left their armies weakened and certainly not fit for battle. Third,They were simply not enough crusaders to effectively settle and colonize the area of Palestine and Syria.They could not provide the presence that was needed to maintain and administrate a kingdom in a largely Muslim populated land. Fourth,far too often the Crusades became about achieving personal victories or political victories instead of freeing the holy land from Muslim domination. Finally,There was not an understanding, or desire to understand, the peoples that they conquered. Their mission had become solely to replace Islam with Christianity instead of allowing the two to coexist peacefully.