Who did the crusaders fight against during the crusades?

During the Crusades, the crusaders primarily fought against Muslim forces in the Holy Land, particularly the Seljuk Turks and later the Ayyubid dynasty, led by figures like Saladin. Additionally, they clashed with various local Christian sects and groups that were seen as heretical, such as the Cathars in the Albigensian Crusade. The overarching goal was to reclaim Jerusalem and other sacred sites for Christianity.