The Lost King - The Bewildering Adventures of King Bewilliam by Devorah Fox

Royalty ruined, redeemed, reunited, resolute. When all you have owned, everyone you have loved, and everything you have done are gone, who are you? King Bewilliam awakens one morning not in his castle but in a cow pasture, inexplicably transformed from a beloved and respected ruler, husband, father, and dragon slayer of renown to a homeless vagabond. What mysterious spell so cruelly reversed his fortune? Who cast it and why? In his quest to uncover and break the curse that plagues him and regain his kingdom he journeys to strange lands where he finds adventure, danger, romance...and himself.