In alliance with Charlemagne and his successors, the Roman popes managed to extend their authority in Western Europe. By the middle of the ninth century, Pope Nicholas I (r. 858–867) succeeded in gaining direct control over the entire Western Church by suppressing the local metropolitans and making all bishops in the West directly subject to the Roman see. In this effort, he made use of the False Decretals, documents that were later decisively proved to be forgeries, which claimed that Emperor Constantine the Great in the fourth century had given extensive powers and privileges to the Bishop of Rome. It was claimed that these powers included having governmental control over large territories in central Italy which later came to be called the Papal States. This particular forgery was the so-called Donation of Constantine.