The unprovoked series of wars which we know as the crusades, has sometimes been justified by some people claiming ‘In the Crusades, Christians we’re trying to win back control of their holy city, Jerusalem.’ However, I don’t think that it’s fair to say this, because, it is also a Muslim and Jew holy city, then owned by the Muslim people. So, it is unfair to let this reason justify the crusade, as, Muslims and Jews have the same right to the city.
During the crusades, the invaders would loot and steal from towns they invaded, so, if the crusades were purely for religious purposes they would have no reason to do this.
Finally, the crusades were political, as, Europe was not doing well economically and there was not enough land in Europe for the people. This is why they invaded the Middle-East and disguised it as a religious entourage to encourage peasants to come and ensure their place in heaven.