 About 1396 he joined the Brethren of the Common Life at Deventer, where personal intercourse with the companions of the founder, especially Florentius Radewyns, thoroughly acquainted him with the spirit and methods of the congregation, then in its first fervour.It is probable that during the plague of 1398 he left Deventer for Amersfort (another Dutch city) with Florentius, on whose death he returned to his native Münster to establish a community there.In any case the records at Münster point to 1400 as the date of foundation.