Reformation Letters is a detailed look at John Calvin's letters, which were mostly of a pastoral nature. These were letters that define the Reformation and demonstrate Calvin's concerns, his strengths, and his weaknesses, against the background of his own time and contemporaries. Here we find Calvin on his own calling and exile from Geneva; Calvin on marriage—his own and others'; Calvin's prefatory letter to Francis I of France; Calvin's letter to Sadoleto on the nature of the Reformation; Calvin on Servetus and the reasons for his trial and execution for heresy; and Calvin's letters to those facing death and persecution.