Who did the Christians fight against the crusades?

During the Crusades, Christians primarily fought against Muslim forces in the Holy Land, particularly the Seljuk Turks and later the Ayyubid dynasty led by figures like Saladin. The Crusades were launched in response to Muslim conquests of territories considered sacred by Christians, including Jerusalem. Additionally, there were conflicts with other groups, such as Orthodox Christians in the Byzantine Empire and various local factions. Overall, the Crusades were marked by a complex interplay of religious, political, and territorial motivations.