This is a new critical edition of the letters of the Franciscan Adam Marsh, spiritual counsellor to many of the leading figures of his generation, in which the Latin text of the letters is for the first time accompanied by an English translation. Adam's correspondents include Robert Grosseteste, Simon de Montfort, and Queen Eleanor, making the letters a primary and exciting source for the history of England, the Church, and the University of Oxford in the turbulent middle years of the thirteenth century.