The term Calvinism was originally coined in a pejorative sense by J. Westphal, a Hamburg pastor and disciple of Luther. Besides the work and impact of the Geneva Reformer John Calvin (1509-1564), he extended it to include the influence of the Zürich Reformation movement led by Ulrich Zwingli (1484-1531) and his followers. Thus Calvinist can be used as a synonym of Reformed, for example in the legal language of the Empire after the Peace of Westphalia (1648).