Devotio Moderna was a movement for religious reform that called for apostolic renewal through the rediscovery of genuine pious practices such as humility, obedience, simplicity of life, and integration into the community. It began in the late 14th century, largely through the work of Gerard Groote, and flourished in the Low Countries and Germany in the 15th century but came to an end with the Protestant Reformation. It is most known today through its influence on Thomas à Kempis, the author of The Imitation of Christ, a book that has proved highly influential for centuries.