During the Middle Ages, the Roman Catholic Church became a unifying institution in Western Europe as it filled the void left by the decline of Roman authority, serving social, political, and religious needs. The church's structure included various ranks, with the Pope at the top, and it played a significant role in education and the preservation of Greco-Roman culture through monasteries. However, the church faced corruption issues, including the sale of church positions and the abuse of power during the Inquisition.