Brethren of the Common Life
Community founded by Geert de Groote (1340-1384), a Dutch priest and mystic.
After spending several years in solitude, he came forth and began to attack the evils of the clergy.
A group of secular priests and lay persons, attached themselves to De Groote and became known as the Brethren of the Common Life.
They took no vows, but aimed at the interior life and devoted themselves to education and literature.
They transcribed numerous manuscripts and founded free schools at Windesheim (1386) at Deventer, where there were 2,000 students in 1500, and in many places in Germany and the Netherlands.
Men like Thomas a Kempis, who wrote a life of De Groote, Pope Adrian VI, and Gabriel Biel, were trained in their schools, which were almost all swept away during the Reformation.
New Catholic Dictionary