Martin Luther posted his Ninety-Five Theses on the church door at Wittenberg in 1517. In the three years that followed, Luther clarified and defended his position in numerous writings. Chief among these are three treatises written in 1520. In these texts, Luther tried to frame his ideas in terms that would be comprehensible not only to the clergy but to people from a wide range of backgrounds. To the Christian Nobility of the German Nation is an attack on the corruption of the church and the abuses of its authority, bringing to light many of the underlying reasons for the Reformation. The second treatise, The Babylonian Captivity of the Church, contains Luther's sharp criticism of the sacramental system of the Catholic church. The Freedom of a Christian gives a concise presentation of Luther's position on the doctrine of justification by faith. This volume is excerpted from The Annotated Luther series Volume 1, The Roots of Reform, and Volume 3, Church and Sacraments. To facilitate classroom and group use, three key treatises are included here, along with their introductions, annotations, and images directly from the Annotated Luther series volumes.