Complex sentence: The Romans soon fell away from their allegiance to the pope; and, recalled to the city, Henry entered Rome in March 1084, after which Gregory was declared deposed and Clement was recognized by the Romans.
Split into simpler sentences: The Romans soon fell away from their allegiance to the pope. Recalled to the city, Henry entered Rome in March 1084, after which Gregory was declared deposed and Clement was recognized by the Romans.