From the 11th century onwards indulgences were granted: In 1064 Pope Alexander II promised the participants of an expedition against Barbastro (Tagr al-Andalus, Aragon) a collective indulgence 30 years before Pope Urban II called the First Crusade.
Later military orders like the Order of Santiago, Montesa, Order of Calatrava, and the Knights Templar were founded or called to fight in Iberia.