"Guerrero" is a Spanish surname. "Leon" is originally "DeLeon" which means "of Leon". Leon being a place in Spain. So in it's entirety it would mean the Guerrero family from Leon. The name Deleon Guerrero probably orginated from the Philipines. At some point the family dropped the "De" from Leon. Most of the Leon Guerrero's on guam have Chamoru blood lines.