The letters in this volume reflect Erasmus' anxiety about the endemic warfare in Western Europe, the advance of the Ottoman Turks into Europe, and the increasing threat of armed conflict between Catholics and Protestants in Germany. Unable and unwilling to attend the Diet of Augsburg (June-November 1530), summoned by Emperor Charles V in the attempt to mediate a religious settlement, Erasmus corresponded with those in attendance, urging them (in vain) to preserve peace at all costs.

The letters also shed light on Erasmus' controversies with Catholic critics (Luis de Carvajal and Frans Titelmans) who accused him of Lutheran sympathies, and former friends among the Protestant reformers (Gerard Geldenhouwer and others in Strasbourg), who embarrassed him by citing him in support of their views. Because of a mysterious and debilitating illness (identified in an appendix to the volume) the twelve months covered were less productive of scholarship than was usual for Erasmus, but it did see the publication of the five-volume Froben edition of St. John Chrysostom in Latin.

Volume 16 of the Collected Works of Erasmus series.