Austrian teacher, organist and composer, born 25 November 1787 in Unterweitzberg in Hochburg-Ach, Austrian Empire and died 7 June 1863 in Hallein, Austrian Empire.
He composed the music to "Stille Nacht" ("Silent Night, Holy Night").
http://www.cyberhymnal.org/bio/g/r/gruber_fx.htm
http://en.wikipedia.org/wiki/Franz_Gruber