Geert Groote (Gerardus Magnus, 1340–1384) was a Dutch preacher, deacon, and reformer of Deventer who, after a worldly youth and university studies at Paris, underwent a religious conversion around 1374 and devoted the rest of his life to the renewal of Christian piety in the IJssel region. Licensed to preach throughout the diocese of Utrecht, he attacked clerical abuses — including simony, concubinage, and the buying of admission to beguine houses — and gathered a community of women in his family home that became the seed of the Sisters of the Common Life; his followers among his student Florens Radewijns and others founded the Brethren of the Common Life shortly after his death. Groote is regarded as the father of the devotio moderna, the late-medieval movement of inward piety and lay spirituality that shaped Thomas à Kempis's Imitatio Christi and the Windesheim Congregation of Augustinian Canons. He died of plague at Deventer while caring for the sick.
