John Calvin (10 July 1509 - 27 May 1564) was one of the most influential Christians of the last millennium. An influential French theologian and pastor during the Protestant Reformation, Calvin was a principal figure in the development of the system of Christian theology later named after him. Originally trained as a humanist lawyer, he broke from the Roman Catholic Church around 1530, and after religious tensions provoked a violent uprising against Protestants in France, Calvin fled to Basel, Switzerland, where he published the first edition of his seminal work Institutes of the Christian Religion in 1536. Calvin was a tireless polemic and apologetic writer who generated much controversy. He also exchanged cordial and supportive letters with many reformers, including Philipp Melanchthon and Heinrich Bullinger. In addition to the Institutes, he wrote commentaries on most books of the Bible, as well as theological treatises and confessional documents. He regularly preached sermons throughout the week in Geneva. Calvin was influenced by the Augustinian tradition, which led him to expound the doctrine of predestination and the absolute sovereignty of God in salvation of the human soul from death and eternal damnation. Calvin's writing and preachings provided the seeds for the branch of theology that bears his name. The Reformed and Presbyterian churches, which look to Calvin as a chief expositor of their beliefs, have spread throughout the world. Some of Calvin's most popular writings were his commentaries on certain aspects of the religion. These commentaries focus on Calvin's ideas about ethics and their role in Christianity.