In 1549, Mažvydas was appointed a priest in Ragainė, in the present-day town of Neman. In the same year he wrote and published "The Song of St. Ambrosy", with a dedication in Lithuanian. In 1554 Mažvydas became the Archdeacon of Ragainė. He oversaw the education of his parishioners, regulated agricultural matters, and continued his literary work in Lithuanian. He translated "The Form of Baptism" from German into Lithuanian and published it in Königsberg in 1559. Between 1558 and 1562 he published "The Prussian Agenda" into the prayer "Paraphrasis", published in Königsberg in 1589, after the death of the translator. Another of his major works is "The Christian Songs" ("Gesmes Chriksczoniskas, Gedomas Baszniczosu Per Aduenta ir Kaledas ik Gramniczu") (Part I, in 1566; Part II, in 1570), printed by his cousin Baltramiejus Vilentas. This book served as a basis for other Protestant books of songs that would later be published in Lithuania Minor.