The main purpose of the Crusades launched by European Christians in the Middle Ages was to reclaim the Holy Land, particularly Jerusalem, from Muslim control. Beginning in the late 11th century, these military campaigns were sanctioned by the Pope and aimed to reinforce Christianity and secure pilgrimage routes for Christians traveling to sacred sites. The Crusades also resulted in cultural exchanges, as they introduced European powers to Eastern knowledge, art, and technology. However, they led to lasting tensions between Christians and Muslims and had profound effects on the political landscapes of both Europe and the Middle East.