There were more than eight. Numbered crusades in the Levant and north Africa total 9. Plus the Baron's crusade between the sixth and seventh. In the Baltic you had the Wendish, Livonian, and Prussian crusades. In the Balkans you had Crusade of Nicopolis, Crusade of Varna, and the Bosnian Crusade. You also had the Babary Crusade, and Alexandrian Crusade. Plus the Aragonese Crusade and Albigensian Crusade (the one against the Cathars). All of these were sanctioned as crusades by the Pope. And cover a period of 400 years.