In the Nasrid Wars, "El Gran Capitán" (The Great Captain), Gonzalo Fernández de Córdoba, was a military man in the service of the Catholic Monarchs (15th and 16th centuries). Belonging to the House of Aguilar, he was trained between the warrior tradition of the Andalusian frontier and the Castilian royal court. In the Nasrid Wars (1480-92), he began to practice his tactical innovations that made him, from a young age, the most outstanding military leader of the Castilian-Aragonese monarchy. He introduced major reforms in the "art of war": from medieval heaviness (heavy cavalry) to modern agility (infantry), he trained his men with rigorous discipline and shaped their morale, awakening in them a sense of corps pride, personal dignity, national honor, and religious interest.
His name was soon associated with bravery. One of the first battles in which he participated was that of Albuera, when he fought against the hosts of the King of Portugal who had invaded Extremadura.
But where he truly began to show his military genius was during the "War of Granada," a military campaign that took place starting in 1482 and in which the Spanish sought to expel Boabdil from the last Muslim state on the Iberian Peninsula. The services he rendered during that campaign were rewarded with the commendation of the Order of Santiago, in addition to other incomes and lordships.
Around 1497, after a brief stay at court, the Catholic Monarchs appointed him "adalid de la Frontera" (champion of the frontier), a rank equivalent to captain.
The successes of the Italian Campaign (the capture of Reggio, Atella, and Naples) earned him the nickname of Gran Capitán and the title of Duke of Santángelo.
The death of Queen Isabel the Catholic in 1504 marked the beginning of the Great Captain's fall from grace. His confrontation with Ferdinand the Catholic reached a climax following the Treaty of Blois (1505), at which point legend has it that he demanded that the Great Captain render an account of his management.
The Cordovan never ceased to be an officer close to his men, with a sense of honor towards the adversary, stoic, and, above all, a loyal subject to the Catholic Monarchs who, on his shoulders, began the adventure of a new nation.
The legacy of the "Gran Capitán" revolutionized the way of fighting worldwide: troop formation into companies under the command of a captain, and the expert handling of individual firearms by the foot soldier.
He gave a fundamental role to cavalry. He replaced medieval shock warfare with the defense-attack tactic, giving preference to infantry over all other weapons.
He made the Spanish infantry that formidable army of which the French said after fighting against it, that "they had not fought with men but with devils."