JONAS, Justus (1493-1555), a German Protestant Reformer, was born at Nordhausen in Thuringia 5th June 1493. In 1506 he entered the university of Erfurt, where he graduated in law in 1516; but, having been converted to the doctrines of Luther, he, about 1519, resolved to study theology. In 1521 he accompanied Luther to the diet of Worms. The same year he was appointed professor of canon law at Wittenberg, where shortly afterwards he became doctor in theology, and occupied himself much in preaching. During the next twenty years he took part in many church visitations and conferences, and translated into German several of the works of Luther and Melanchthon. In 1541 he became superintendent of the churches at Halle, whence he was banished by the elector Maurice of Saxony in 1546. He returned for a short time in 1547 and again in 1548, but was unable to resume his interrupted tasks; after a short stay at Jena, where he had some share in the ordering of the new university, he became court-preacher at Coburg in 1551. In 1553 he was called as first pastor to Eisfeld, where he died 9th October 1555. Among the theological tractates of Jonas is Discussio pro conjugio sacerdotali, 1523. He also wrote an account of the proceedings of the conference of Marburg.

See Reinhard, De Vita et obitu Justi Jonae, 1713; Knapp, Nar ratio de Justo Jona, 1817; and the life by Hasse in Meurer’s Leben der Altväter der luth. Kirche, 1864.