early leader of German Pietism. Influenced by the works of J. Arndt and the English Puritans, and by J. de Labadie (see Labadists), he became convinced of a call to revivify the Lutheran Church with evangelical fervour. At Frankfurt, where he was appointed minister in 1666, he introduced ‘Collegia Pietatis’, devotional meetings which gathered twice a week in his house; and he issued his Pia Desideria (1675). While he remained loyal to the Lutheran tradition, the personal and interior turn of his religion made him critical of a sterile and polemical form of orthodoxy. He also tried to give the laity an active part in Church life. In 1686 he went to Dresden as court preacher. He came into conflict with the theology faculty of the University of Leipzig and in 1691 migrated to Berlin. His movement, by then known as ‘Pietism’, spread, and in 1694 the University of Halle was founded, largely under his influence.