Johann Christoph Altnickol
From pipe-organ.wiki
Johann Christoph Altnickol (1720-1759) was a German organist. In 1744, he was the student of Johann Sebastian Bach, and in 1749 he became Bach's son in law. Starting in 1748 he was the organist in Naumburg.
References
Beckmann, Klaus, Die Norddeutsche Schule. Teil II: Blütezeit und Verfall. Mainz: Schott, 2009. 227.