1350-1400. Follower of ,* he helped found the Brethren of the Common Life.* He studied at Prague, became a canon at Utrecht, and was converted to a serious Christian life by Groote's fiery preaching. At his suggestion, and with his help, Groote founded the Brethren, to be devoted to the cultivation of practical piety. After Groote's death in 1387, Florentius became leader of the movement and formed the Congregation of Windesheim, with regular canons, associated with the Brethren. Under his leadership the Brethren expanded rapidly. If Groote founded the movement, Florentius was its organizer. During the 1400s it was to become a major devotional and educational force in the . Florentius also wrote several brief devotional works (e.g., Tractatus devotus de extirpatione vitiorum).