Buckland Filleigh's registers "only" go back to 1619.
There is a will of a Hugh Fortescue of Weare Giffard who died in 1600.
https://www.ancestry.co.uk/imageview...96c&pId=923864 I suspect he is a son of "the" Hugh Fortescue of Buckland Filleigh as his daughter Marie appears to be unmarried (and he clearly has a financial arrangement tying up his daughter Rebecca in marriage to William Lee)
He looks as if he is the trustee mentioned in John Upton's will as he has a son John and a brother George. The unnecessarily convoluted style of the will suggest that it was drawn up by the same advisors that drew up John's will. So probably a brother in law.