He was elected King of the Germans (Emperor Elect) in 1054 having succeeded his father in 1056, his mother being regent. About 1070 he began to act for himself. His first task was to break the power of the nobles; but his measures provoked a rising of the Saxons who, in 1074, forced humiliating terms upon him. In 1075 he defeated them at Hohenburg and then proceeded to take vengeance upon the princes, secular and ecclesiastical, who had opposed him. 
The case of the latter gave Pope Gregory VII a pretext to interfere in the affairs of Germany. This was the beginning of the great duel between pope and emperor. In 1076 Heinrich declared the pontiff deposed. Gregory VII retaliated by excommunicating the emperor. 
Heinrich IV, seeing his vassals and princes falling away from him, hastened to Italy to make submission at Canossa as a humble penitent, and, in January 1077, the ban of excommunication was removed. Having found adherents among the Lombards, Heinrich IV renewed the conflict, but was again excommunicated. He thereupon appointed a new pope, Clement III, then hastened over the Alps to besiege Rome and, in 1084, caused himself to be crowned emperor by the antipope. In Germany during his absence, three rival kings of the Germans successively found support, but Heinrich IV managed to triumph over them all. 
He had crossed the Alps for the third time (1090) to support Clement III, when he learned that his son Konrad had joined his enemies and been crowned king at Monza. Disheartened, he retired to 
Lombardy in despair, but at lenth returned (1097) to Germany. His elder son, Heinrich, was elected King of the Germans and heir to the empire. This prince, however, was induced to rebel by Pope Pascal II; he took the emperor prisoner and compelled him to abdicate. The emperor escaped, however, to find safety at Liege where he died.
 

Source: Leo van de Pas