''''''Wo Gott der Herr nicht bei uns hält''''' is an organ chorale fantasia written by the composer Johann Sebastian Bach, BWV 1128. It is based on the Lutheran hymn (1524) by Justus Jonas. The manuscript was recently discovered on 15 March 2008 at an auction of items from the collection of Wilhelm Rust (1822-92).[http://wayback.archive.org/web/20110721145157/http://thediapason.com/BWV-1128-A-recently-discovered-Bach-organ-work--article9863 BWV 1128: A recently discovered Bach organ work] The first public record of this chorale fantasia is 1845, almost 100 years after Bach's death, listed among organ pieces by "Sebastian Bach" in the estate auction for Johann Nicolaus Julius Kötschau, once organist at St. Mary's in Halle (Saale). According to public record, he acquired the pieces in an 1814 auction along with the "Clavier-Büchlein of Wilhelm Friedemann", Bach's son and once an organist in Halle, who had passed the scores on to his distant relative and student Johann Christian. Kötschau, who apparently was reluctant to share his prize collection, eventually relented, first loaning it to Felix Mendelssohn, and then to the Leipzig publishers C. F. Peters. However, there is no evidence that anyone recognized the significance of what they saw.