II (AD 821-829), and testifies that they observed Sabbath. As late as the 11th century Cardinal Humbert still referred to the Nazarenes as a Sabbath-keeping Christian body existing at that time. But in the 10th and 11th centuries, there was a great extension of sects from the East to the West. Neander states that the corruption of the clergy furnished a most important vantage-ground on which to attack the dominant church. The abstemious life of these Christians, the simplicity and earnestness of their preaching and teaching, had their effect. "Thus we find them emerging at once in the 11th century, in countries the most diverse, and the most remote from each other, in Italy, France, and even in the Harz districts in Germany." Likewise, also, "traces of Sabbath-keepers are found in the times of Gregory I, Gregory VII, and in the 12th century in Lombardy." Oriental Orthodoxy The Orthodox Tewahedo churches celebrate the Sabbath, a practice proselytised in the Oriental Orthodox church in Ethiopia in the 1300s by Ewostatewos (, ). In response to colonial pressure by missionaries of the Catholic Church in the 1500s, the emperor Saint Gelawdewos wrote his Confession, an apologia of traditional beliefs and practices including observation of the Sabbath and a theological defense of the Miaphysitism of Oriental Orthodoxy. Protestant Reformation Protestant reformers, beginning in the 16th century, brought new interpretations of Christian law to the West. The Heidelberg Catechism of the Reformed Churches founded by John Calvin teaches that the moral law as contained in the Ten Commandments is binding for Christians and that it instructs Christians how to live in service to God in gratitude for His grace shown in redeeming mankind. Likewise, Martin Luther, in his work against the Antinomians, rejected the idea of the abolition of the Ten Commandments. They also viewed Sunday rest as a civic institution established by human authority, which provided an occasion for bodily rest and public worship. Another Protestant, John Wesley, stated "This 'handwriting of ordinances' our Lord did blot out, take away, and nail to His cross. But the moral law contained in the Ten Commandments, and enforced by the prophets, He did not take away. ...The moral law stands on an entirely different foundation from the ceremonial or ritual law. ...Every part of this law must remain in force upon all mankind and in all ages." Sabbatarianism arose and spread among both the continental