The Crusadeswere a series of wars during the Middle Ages where the Christians of Europe tried to retake control of Jerusalem and the Holy Land from the Muslims. The "Holy Land" is part of the region we call the Middle East today.
Why did they want to control Jerusalem?
Jerusalem was important to a number of religions during the Middle Ages. It was important to Jewish people as it was the site of the original temple to God built by King Solomon. It was important to the Muslims because it is where they believe Muhammad ascended (went up) to heaven. It was important to Christians as it is where they believe Christ was crucified (killed) and rose again.
Who fought in the Crusades?
The Crusades were between the armies of Europe, mostly the Holy Roman Empire, and the Arabs that had control of Jerusalem. There were around 30,000 soldiers from Europe in the first Crusade, they were made up of Knights, peasants, and other commoners. Some saw the army as a way to get rich and try out their fighting skills, while others saw it as a way into heaven.