medieval Christian fellowship that originated during the early part of the 14th century in Basel, Switz., and then spread to Germany and the Netherlands. Primarily a middle-class, democratic lay movement espousing a Christian life of love, piety, devotion, and holiness, the Friends of God presaged the 16th-century Reformation. Some of its leaders, attacking corruption in the Western church and expecting a subsequent intervention of God, were tried and executed for heresy.