Until 1555 the Netherlands were part of Charles V’s multinational Habsburg Empire. Charles clearly considered the Spanish kingdoms, especially Castile, the core of his monarchy. However, Charles traveled continuously throughout his vast territories and personally participated in many wars, from west and central Europe to North Africa. Despite his long absences, his subjects in the Low Countries accepted Charles as their rightful and “natural” sovereign. His son, Philip II (r. 1555–1598), on the other hand, was born and educated in Spain. During his forty-four-year rule, Philip spent less than five years away from the Iberian Peninsula.