When the Crusaders conquered Jerusalem, the city underwent significant change. Jews and Muslims no longer peacefully coexisted with Christians. French (the language of the Franks) became the predominant spoken language. Latin was the language of the church.
After Baldwin I’s death, in 1118, his successors continued to rule the new Kingdom of Jerusalem. A Second Crusade, to strengthen the borders of the kingdom, failed miserably. The Franks had alienated other Christians in the area, including Greek Orthodox, Coptic and Armenian Christians. (It didn’t help when they referred to other Christians as heretics.)
Muslims, meanwhile, wanted to recapture the territory, including the city of Jerusalem (which is third-holiest in Islam, after Mecca and Medina). A new, ambitious young ruler, Salah al Din Yusuf Ibn Ayyub - whom we know as Saladin - had risen in the ranks to become a powerful leader. A Kurd (not an Arab) from Tikrit (the birthplace of Saddam Hussein), Saladin believed God had called him to liberate Palestine.
A charismatic man who did not consider himself better than others, Saladin mixed with his people. He was devoted to the idea of a holy war as a defense against the Franks. He was also a winning warrior and mounted successful attacks which further encroached on land held by the Franks.
Arabic primary sources say little of his physical appearance:
Those who knew Saladin say little about his physical appearance: he was small and frail, with a short, neat beard. They prefer to speak of his pensive and somewhat melancholy face, which would suddenly light up with a comforting smile that would put anyone talking to him at ease. He was always affable with visitors, insisting that they stay to eat, treating them with full honours, even if they were infidels [a term both sides applied to each other], and satisfying all their requests. (The Crusades Through Arab Eyes, page 179)
Saladin had another characteristic worth noting:
In general, one may say that Saladin was as demanding of himself as Nur al-Din [his predecessor] had been, but more lenient with others, although he was even more merciless than his elder when dealing with those who had insulted Islam, be they “heretics” or certain of the Franj [the term Muslims used for the Franks]. (The Crusades Though Arab Eyes, page 180)