Alonso de Cárdenas was a Spanish noble who served as the 44th and 47th (and last) Grand Master of the Order of Santiago before the title passed to the Catholic Monarchs as the need for a powerful military order outside the direct control of the king ceased to exist with the end of the Reconquista. He is famous for building the castle at Puebla del Maestre in 1483. He was also the father of García López de Cárdenas.
Alonso was a member of the House of Cárdenas, a relatively new family that would become increasingly powerful in Spain's colonial possessions in the New World. He was the father of García López de Cárdenas who would go on to discover the Gran Cañón del Colorado, what is today known simply as the "Grand Canyon".
Alonso de Cárdenas served the Catholic Monarchs during the War of the Castilian Succession. One of the captains under his command was Gonzalo Fernández de Córdoba, also known simply as the "Gran Capitan" for his considerable military exploits throughout Spain's European empire. After the Battle of Albuera, Alonso singled the Gran Capitan out for praise stating that he had always seen the captain leading his troops from the front, a fact he was sure of due to the splendor of his armor.
Throughout his life, he had to engage in continuous power struggles to obtain and maintain power. With the finalization of the Spanish Reconquista, there were fewer and fewer possibilities to contribute militarily to the crown. For this reason, the struggles for power in contemporary Spain left the battlefield and were concentrated more on the political front.
He was Grand Master of the Order of Santiago during two separate terms: the first was from 1474 to 1476 and the second lasted from 1477 to 1493, the last year that the order existed in a semi independent form from the Spanish crown.