The First Crusade was the most successful. Armies from Europe drove out the Turks and took control of Jerusalem.
In 1146 the city of Edessa was conquered by the Turks. The entire population was killed or sold into slavery. Then a second Crusade was launched, but was unsuccessful.
In 1187 Saladin, the sultan of Egypt, recaptured the city of Jerusalem from the Christians. A third Crusade was launched led by Emperor Barbarossa of Germany, King Philip Augustus of France, and King Richard the Lionheart of England. Richard the Lionheart fought Saladin for several.
The Fourth Crusade was formed by Pope Innocent III with the hope of taking back the Holy Land. However, the Crusaders got sidetracked and greedy and ended up conquering and plundering Constantinople instead.
Started by a French child named Stephen of Cloyes and a German kid named Nicholas, tens of thousands of children gathered to march to the Holy Land. This ended in total disaster. None of the children made it to the Holy Land and many were never seen again. They were likely sold into slavery.
Over the next several years there would be 5 more Crusades. None of them would be very successful in terms of gaining control of the Holy Land. Interesting Facts about the Crusades