lets say the new King of Spain goes out for a ride, his horse steps in a mole hole and Philip goes flying and brakes his neck and dies, that leaves his Sister Isabella as Queen, now does she rule by her self? or with her Husband Archduke Albert of Austria as the couple did in OTL in the Spanish Netherlands? if the couple (as in OTL) have no Kids who takes the Throne? what is Isabella's Rule like? and what becomes of the Spanish Netherlands? how are they changed by not having Isabella and Albert rule them separately from the rest of Spain?