Thomas à Kempis
He was a member of the Congregation of Windesheim, which was part of the Modern Devotion, a reform movement during the late medieval period. Therein, he was a follower of Geert Groote and Florens Radewyns, the founders of the Brethren of the Common Life, of which the Windesheim Augustinians were an offshoot. Provided by Wikipedia
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