Exclusive Video: Josh Groban Discovering Remarkable and Controversial Ancestor

(courtesy of TLC)

Josh Groban knows little about his mother's lineage, so sets out on a journey to learn more about the maternal side of his family tree on Who Do You Think You Are?, airing this Sunday, March 15 at 10/9c on TLC.

Josh traces his ancestors' roots from Los Angeles to Germany and follows the trail of his 8th great-grandfather, discovering a brilliant man who was a deacon, author, well-known astrologer (admired by Sir Isaac Newton), and music and singing teacher. But Josh also discovers that his ancestor's predictions of cataclysmic doom put him in the crosshairs of the church and the fate of his family on the line. Take a sneak peek:

To whet your appetite for Sunday's show, here are 10 ancestral tidbits about Josh Groban's roots.

Next up? Angie Harmon.