The clash, which took place on Nov. 16, 1532 in what would later become Peru, saw an 80,000-man Incan army utterly routed by a token force of just 168 Spanish Conquistadores in a matter of minutes.
The violence erupted when the Spanish explorer Francisco Pizarro, along with a handful of soldiers and mounted horsemen, met the powerful Inca ruler Atahuallpa for the first time. The 62-year-old conqueror was on a mission to claim the whole region for His Most Catholic Majesty Charles V and openly announced his intentions to his wary host. Although the Spanish were far from friendly territory and outnumbered nearly 500 to 1, the wily Pizarro decided to follow up his words with a show of force. Right on cue, his men loosed a volley from their arquebuses and four small cannon while the Spanish cavalry, which until that moment had been concealed in the undergrowth, charged straight into the ranks of Atahuallpa’s retinue. The Incans shrunk back in horror, having never before heard gunfire or seen horses. Within seconds, the attackers had slashed their way through the imperial guards and yanked the dumbfounded emperor from his bejeweled litter. Almost immediately, the Incan army dissolved in panic; Pizarro’s riders tore off in hot pursuit. “It was an astonishing sight,” wrote Diamond. “The whole valley for 15 or 20 miles was completely filled with Indians.” By the end of the day, 6,000 Incan soldiers were dead.
Pizarro held Atahuallpa captive and demanded a king’s ransom (literally!) for his life. The Incans in turn delivered enough gold to fill a banquet hall in hopes of freeing their abducted king. But once the booty was safely in hand, the bloodthirsty Spaniard reneged on the deal and had the emperor garroted. Gradually, the Inca civilization was consumed by the invaders.
While Atahuallpa legions suffered a singular defeat at Cajamarca unparalleled in all of military history, for decades prior to the fateful clash, the Incan army was virtually undefeated and dominated half of South America. Here are some amazing facts about this little-known imperial fighting force.
The Biggest Army in the Americas – At its peak in the early 16th Century, the Incan Empire was home to 20 million citizens and spanned more than 2 million sq. km (800,000 sq. miles). The largest of the pre-Columbian civilizations in the New World, the Incas maintained an army as massive as the largest European states of the time. At any given moment, the supreme ruler or Sapa Inca could field as many as 200,000 troops drawn from the realm’s various regions.
Order of Battle – The emperor’s forces were organized into divisions consisting of 10,000 soldiers. An aristocrat known as an Apusquin Rantin – the equivalent of a major general – was appointed to commanded each of the units. The armies were raised from the various assimilated territories that made up the Inca civilization. Each was manned by soldiers from the same tribe. Units typically wore distinctive uniforms to represent their native region. It was a multicultural army for a polyglot empire.
Citizen Soldiers — The rank-and-file in the Incan army were conscripts known as Aucac Runas. All able-bodied male commoners between the ages of 25 and 50 were obligated to serve at least one seven-year tour of duty during their lifetime. A lottery determined who served and when. At any given moment as many as 2 percent of the adult male population served.
Leadership — Incan officers weren’t draftees, but rather professional career soldiers specially trained to command. Recruited from the upper strata of society, they were paid a salary commensurate with their military rank and further rewarded for their service with gold, coca and even women. Officer candidates were chosen annually at a religious festival known as Warachikuy. Prospective leaders would demonstrate their suitability through demonstrations of strength and endurance. These included foot races, mock battles and competitions to see who could go the longest without sleep.
Weapons and Equipment — The Incan arsenal was nothing if not diverse. Missile weapons included slings, throwing bolas and large bows that could shoot six-foot-long arrows. Bone-crushing implements including star-shaped stone clubs and axes known as cuncha chucunas or “neck-breakers” were also popular, as were sharpened wooden swords called Macana. Spears of varying lengths were commonly used as well, some as long as 20 feet. Armour usually consisted of garishly painted helmets, shields and breastplates all of which were made of wood or hides. Officers or soldiers that had served with distinction might be awarded with copper or silver-coated equipment.
Light Infantry — Despite the absence of horses in the pre-Columbian Americas, Inca armies were able to travel vast distances quickly, thanks in part to the intricate networks of roads that crisscrossed the rugged mountainous empire. High-altitude fortresses and depots known as Qollcas dotted these routes allowing armies in transit to rest and resupply while on the march. Soldiers were permitted to bring their wives on campaign with them, many of whom would cook and tend to the wounded and sick.
Psychological Warfare — Incan armies excelled at intimidation and consequently rarely needed to fight. Often the sheer size of the emperor’s forces cowed opposing factions into submission almost immediately. If conflict was unavoidable, confrontations often began with the colourful Incan armies pouring onto the field in precision parade formations intended to awe the opposition. Inca battalions often executed these intricate manoeuvres in total silence, which helped demonstrate to foes the army’s rigid discipline and professionalism. If that didn’t break the enemy’s will, high priests that accompanied the troops into the field might cast spells or curses on opponents in hopes of further sapping morale. If these mind games failed produce a surrender, the Incans used force to carry the day.
On the Battlefield — The Incans typically began battles by sending in their archers as well as sling and bolas bearers. Their barrages of missiles were intended to soften up the enemy. Assault troops armed with clubs and axes would then move forward to press the attack, followed by spearmen. The armies typically mounted full frontal assaults, while units on either flanks would attempt encirclements. Few tribal armies had the numbers to match an Incan onslaught, so military actions were usually brief but bloody affairs.
Elite forces – The Incans regarded their emperor as a living deity; nothing was spared when it came to his safety. The army combed its battalions for the bravest and best warriors to serve on the ruler’s own 10,000-man elite bodyguard. This praetorian guard of sorts protected the ruler on the field and accompanied him as he travelled the empire.
Civil War — The Incan Empire reached its nadir on the eve of the Spanish conquest. The mightiest ruler in its history, Huayna Capec died of a mysterious illness in 1527 (possibly from smallpox that was introduced to the continent by European colonists). Prior to his death, the king split his massive realm into two halves and placed his sons on the throne of each new territory – Atahualpa, 30, ruled the north, Huáscar, 36, controlled the south. Soon, the two brothers were at war with each other for supremacy of the whole. Atahualpa was fortunate enough to have the empire’s two most talented generals on his side: Quizquiz and Chalcuchimac, but the war was still raging when the Spanish arrived in 1532. Following Pizarro’s conquest, the Incans rebelled defeating the Spanish at the Battle of Ollantaytambo in 1537. The insurgents were eventually crushed. More mutinies erupted sporadically in Peru over the next four decades until 1572 when the last Incan emperor, Tupaq Amaru, was captured and hanged.