The Christians where the Crusaders as they started the Crusades
Islam
The Crusaders were the Christians. That was the whole point. They were going to recover the Holy Land from the Muslims.
Saladin led the Muslim armies in their opposition to the Christian Crusaders.
The Muslim defenders soundly defeated the Christian crusaders who were attempting to capture Damascus. The crusaders returned to their homelands with the remnants of their armies, and that was the end of the Second Crusade.
Muslim Invaders? Lie. Christian Crusaders tried taking the holyland, not the other way around. But they were called Crusaders, since they Crusaded to the Holy Land.
It started by the Crusaders invasion of Islamic lands along the Eastern side of the Mediterranean sea.
The Muslim forces, led by Saladin, retook Jerusalem from the Christian crusaders in 1187 after the Battle of Hattin. This battle was a decisive victory for the Muslims and led to the collapse of the Crusader states in the Holy Land.
Islam
A General named Saladin led the Muslim Army to retake Jerusalem and the Holy Land from the Crusaders.
Generally it was the crusaders invading Muslim territory, but many battles were also prompted by Muslim warriors ambushing the Crusaders
One effect of the Crusades on Muslim kingdoms was the strengthening of military defenses and unity among various Muslim rulers in response to the threat posed by the Christian Crusaders. The Crusades also led to increased trade and cultural exchanges between Muslim and Christian regions, influencing the development of both civilizations.
Violently. After the siege was able to break the walls of the city and the Christians invaded, the Christian Crusaders killed so many Jewish, Muslim, and local Christians (all civilians) that the blood was rumored to have filled the streets all of the way to the horses' knees.