From hymnary.org: Heinrich Müller was a native of Nürnberg. In about 1526 or 1527 he was imprisoned as a Lutheran by Duke Georg of Saxony, but was released after the Duke died on 17 April 1539. Thereafter, till about 1580, he kept a school for writing and arithmetic at Annaberg in Saxony. Bartholom äus Muller, sometime schoolmaster at Zwickau in Saxony, in a petition presented to the Elector Christian I in 1587, and in another petition presented to the Elector Christian II in 1601, described himself as the son of this Heinrich Müller, and declared that the hymn "Hilf Gott, dass mir gelinge" was written by his father during his imprisonment.