Reformer. He came under the influence of J. Faber (Stapulensis) and adopted Protestantism in the early 1520s. He prepared the first Protestant liturgy in French and in 1529 published his famous Sommaire, a declaration of Protestant belief. He introduced the Reformation in Neuchâtel in 1530, and with P. Viret established it in the Canton of Vaud and in 1534–6 in Geneva. He later returned to Neuchâtel, where he put into practice the Genevan Reformation model.