The genealogy study of the Spanish Hapsburgs shows the dangers of consanguineous unions. However, beyond genealogy, it also had a significant impact on history. Charles II was unable to produce offspring and his death triggered the War of the Spanish Succession (1702-1713). This resulted in several claimants to the Spanish throne, as shown in the family tree below. This family tree also shows how closely the royal families of Europe were related to each other.