Check out this link...
http://www.johnsevierchapter.org/timeline.htmHere's a little blurb about the family that might help. :)
1685 - Some of the family of St. Francis Xavier, living at Xavier, and bearing the name of the town as a family name, had embraced the Protestant religion, and one of them, a devout young Huguenot, Don Jaun Xavier, left France after the revocation of the Edict of Nantes (1685) by Louis XIV. He settled in London, gradually changed the family name to Sevier, pronounced like the English adjective "severe," and his first name to John. He married a London girl named Smith. This was the grandfather of General John Sevier (Folmsbee, Stanley J. John Sevier Empire Builder).