How many early crusades were there What was the common factor?

There were a total of nine major crusades, with the first four considered the early crusades: the First Crusade (1096-1099), the Second Crusade (1147-1149), the Third Crusade (1189-1192), and the Fourth Crusade (1202-1204). The common factor among these early crusades was the desire to reclaim Jerusalem and other holy sites in the Levant from Muslim control, driven by religious fervor and the promise of spiritual rewards.