The warrior group that played a significant role during the Crusades in the Middle Ages was the Knight Templar. Founded around 1119, this military order was formed to protect Christian pilgrims traveling to the Holy Land. The Templars became renowned for their military prowess, and they established a network of fortifications and banking systems across Europe and the Middle East. Their influence reached its peak during the Crusades, where they fought fervently in battles such as the Siege of Jerusalem. However, their eventual downfall in the early 14th century marked a significant end to their power and prominence.