Throughout the Middle Ages, the Catholic Church continued to assert its primacy of position. The growth of the papacy had paralleled the growth of the church, but by the end of the Middle Ages challenges to papal authority from the rising power of monarchical states had resulted in a loss of papal temporal authority. An even greater threat to papal authority and church unity arose in the sixteenth century when the unity of medieval European Christendom was irretrievably shattered by the Reformation. Martin Luther was the catalyst that precipi ....