If this is the correct line for my Sevier family, the original name was Xavier taken from a village, of the same name. It has it's own castle. Legend has it a female was the last in her line. She married a man who took on her noble line, name and all, to help keep this family line going, as it were. Don't know if this helps or not, but titles can be transferred. The kingdom, Navarre, which at that time was leaning more toward France. (To the point that when King Henry of Navarre passed away, the people enticed Henry of France to become their king.) That is until Spain went to war and claimed Navarre as their own. Just recently, Spain was ever so gracious to allow Navarre to fly their own flag. Navarre sits in the Pyrenees that wraps around between the border of Spain and France.