This is a collection of the surviving 33 letters of the German bishop, Lullus of Mainz, originally composed in Vulgar Latin. The Letters of Lullus of Mainz offer a rare and insightful glimpse into the intellectual and ecclesiastical life of early medieval Europe. Written by Lullus, an Anglo-Saxon missionary and the first archbishop of Mainz in the 8th century, the letters reflect his deep involvement in the Christianization of the Germanic peoples and his close ties with figures like Boniface and Pope Zachary. Through these correspondences, Lullus demonstrates a keen awareness of theological issues, ecclesiastical administration, and the challenges of missionary work in a volatile frontier environment. The letters also highlight his diplomatic skills, as he frequently negotiated with both secular and religious authorities.