Inca army The Inca Army was a multi - ethnic army charged with defending the sovereignty of the Incan Empire , expanding its borders , and putting down rebellions . It was also often used for political purposes , such as executions or coups . As the Incan Empire grew in size and population , the army did the same . At the height of the empire ( under the reigns of Tupac Yupanqui and Huayna Capac ) , the army grew to approximately 200 , 000 men . The militaristic nature of the Incan monarchy caused great emphasis to be placed on the army and the position of the common soldier . Soldiers were given food and clothing and state aid was also provided for a soldier ' s family to ensure that agricultural production did not suffer due to the absence of a productive worker . For these reasons full - time soldiers were held in high regard and they even occupied their own position in the socio - political pyramid . When the army returned to Cuzco following a successful campaign they were received by women and children as heroes in a ceremony held in their honor . The ceremony took place in the Plaza de Armas in Cuzco and consisted of exhibiting the plunder and parading the prisoners as a symbol of the victory . Composition . As the Inca empire grew , the army of peasant warriors was replaced by an army with professional officers . Officers were chosen during the " Huarachicuy " festival during which candidates had to undergo various tests of physical skill such as racing , marksmanship , simulated combat and battle drill . There was even a competition to see if they could stay awake for a long period , and in fact it is reported that some officers could remain awake for a whole week . Inca battalions contained permanent staff ( generals and officers ) and non - permanent personnel composed of drafted " hatun runa " s ( common men ) who would be serving their military mita public service ( comparable to a mandatory military service ) . Once the mita was fulfilled , each hatun runa would return to their respective ayllu ( community ) . Each battalion was made up of a single ethnic group , the whole group being directed by a Curaca ( warlord ) who had the same ethnicity . In the event that a Curaca fell in battle a replacement was appointed from within the same ethnic group . In order to prevent rebellions and to promote performance in battle , each ethnic group was divided into two battalions , each one under the command of a general ( and both under the command of the Curaca ) , who would compete against his counterpart in displaying bravery on the battlefield , thus increasing his chances of promotion . This concept of " duality " is widespread in the Andean world , and represents the two Inca dynasties : Hanan and Hurin . Since the government of Tupac Yupanqui , a specialized elite group of soldiers was appointed for the safekeeping of the Sapa Inca ( The One and Only Inca ) during parades , travel or campaigns . These bodyguards originated primarily in Cuzco , even though with time outstanding soldiers from other ethnicities were accepted into the group . This imperial guard , all of them belonging to the nobility , reached a size of 10 , 000 . All members of the Inca army were between 25 and 50 years old . All of the empire ' s citizens had to perform either military or community service . One of every 50 men over 25 years old ( legal age in the Inca Empire ) would be chosen for military service . For noblemen , this was an honor and a duty , for common men , it was a means of social promotion . In accordance with the duality concept , one of every 50 young women were selected to serve in the Temple of the Virgins of the Sun . After a certain period of time ( usually 6 or 7 years ) , the military service was considered to be fulfilled for common men . However , professional officers were permanent soldiers and paid by the state . This military caste enjoyed several privileges as the State paid for their food and housing costs as well as clothing and several other gifts such as coca , jewelry , and wives . Runas ( common men ) from the coastal region , unlike people from the highlands , were not compelled to serve in the army . This is probably explained by their lack of adaptation to the harsh climate conditions of the highlands , where most wars took place . It is worth noting that the army units would march in the company of a large number of women , mostly relatives of the soldiers . Women would take care of cooking and repairing the soldier ' s clothes and after battles would attend the wounded and help bury the dead . Inca armies would not fight at night for religious reasons . A group of priests would also be attached to the army units , in order to pray , make sacrifices , and try to weaken the opposing force by casting spells before and during battle . Weapons and other equipment were transported by llama s . During the beginnings of the Incan empire the army was mainly formed of ethnic Inca troops , however , later on only the officers and imperial guards were Incas ( the Incas were 40 , 000 to 100 , 000 strong and they ruled an empire of 10 to 15 million ) . The squads were organized according to the ethnicity of the soldiers ( auca runas ) , they were armed and dressed according to their tribe , with animal skins , fabric shields , feathers , jewels or body paints . Once a battle was over , enemy leaders would only be executed if they refused to accept the sovereignty of the Incas . The majority of conquered nations would be absorbed into the Empire . Conquered nations were forced to adopt Quechua as their main language , worship Inca gods and adopt Inca social customs . Inca government officials would perform a careful study of the conquered zone to ensure the achievement of these objectives . Tactics . The extensive road system built by the Inca Empire was meant both to facilitate commerce and to allow rapid deployment of the army ( similar to the Roman road system ) . A military action would usually be initiated by a military parade to arouse awe in the opposing army . The soldiers would march with their banners and the commander would be carried in his litter carrying the symbol of his command . Should the opposing force still be willing to fight , the general in command ( or the Inca himself ) would review the troops while musical instruments were played . After this , the commanding officer would rally the troops for the attack . The Sapa Inca himself would rally the troops in larger campaigns , while for smaller rebellions , barbarian invasions , or small campaigns , a general or a prince would be sent as his representative . The Inca army ' s military effectiveness was based in two main elements : logistics and discipline . In order to facilitate the movement of their armies , the Inca built a vast road system . Staging areas were set along the roads so the troops and animals could rest , and weapons could be readied . Discipline was very rigid . Soldiers were not allowed to leave the battalion , not even during the approach march . Troops would maintain silence , only breaking it just before attacks by yelling and singing in order to intimidate the opposing force . Army squads were organized in the following manner : The front lines were initially occupied by slingshot bearers and archers , which would go to the rearguard of the formation after the initial barrages . The lines behind them were occupied by storm - troopers with clubs and axes , then short - spear bearers and closing the formation long - spear bearers ( up to 6 meters long ) . During a battle on open ground , the Inca army would usually be divided into three groups . The main group would launch a frontal attack against the opposing force while the other two would flank it and circle around behind it to attack from the rear . Before the hand - to - hand combat would start , the Inca army would use ranged weapons ( slingshots , arrows and short spears ) in order to break the enemy ' s lines . The army would also feign a retreat , then when the enemy attacked the Incas would counter - attack using a pincer movement . Most enemies in the region were poorly organized and would perform mass frontal charges after breaking formation . As a matter of fact , the Inca army was so well disciplined that it would not often break formation , being able to effectively repel ambushes in jungle , desert , mountain and swamp terrains . In the event that the opposing force would take refuge in a fortress , mountain or city , the Inca forces would cut communication and supply lines in order to isolate the enemy and prevent retreat or requests for reinforcements . If negotiations failed , the Inca forces would attempt to storm the fortress and / or starve the opposing force . Occupied cities and their inhabitants were usually well treated if they surrendered without resistance . However , if the enemy did resist then they could suffer a number of punishments depending on the degree of resistance offered . If a city or tribe surrendered and then rebelled the Inca could even authorize the complete annihilation of the city or ethnic group ( as was the case with the Pastos and the Punaeños ) . Should retreat be necessary the Inca army would usually march along roads in a disciplined manner along the quickest route available . The army would only rest in fortresses with the objective of re - arming should a counterattack be made . Garrisons would be left in the fortresses that controlled the roads in order to delay a possible advance by the enemy . A big advantage for the Inca army over its enemies was its numeric superiority . While adversaries were usually warriors from a single tribe ( or at most , an alliance of several tribes ) , the imperial troops were formed of men from all over the empire . Thanks to the large size of the empire , hundreds of thousands of warriors could be mobilized . This wide variety of men would prove both an advantage ( numerical superiority and specialized soldiers for different terrain ) and a disadvantage ( lack of cohesion between army battalions ) . Both Inca oral histories and Spanish written accounts estimate the Incas could field armies of 100 , 000 at a time . The Incas usually sent scouts to watch their enemies , they would also send groups of nobles to negotiate peace treaties and on a number of occasions the servants that they took were spies that tried to bribe enemy officers so that they would betray their kings by retreating during a crucial moment in a battle . There was a reward system in place for distinguished services . Soldiers displaying bravery beyond expectations were rewarded with medal s , metal weapons or other objects and uniforms . The Incas also built forts ( pucará ) where they stored arms , food and reserve soldiers . These fortresses also controlled the main communication routes and were constructed in easily defended locations such as in mountains and on the tops of hills or at the side of a river or road . Structure . The Inca army was divided in the following manner : The largest units in the Inca army were composed of 10 , 000 men , under the command of a Major General or " Apusquin Rantin " . This was generally a nobleman from Cuzco who would have been a veteran of several campaigns . The head of the field army was the " Apusquispay " , he would have been a noble chosen by the Inca and he would have shown himself to have been in good physical and mental condition at the Huarachico trials . In order to give orders the generals used conche blowers , trumpeters or drummers to communicate with their lieutenants . Equipment . Inca soldiers carried several types of simple weapons , according the ethnic group to which they belonged . For example , Chanca soldiers preferred the use of clubs or macana s , while Antisuyu ( Jungle highlands ) troops more often leaned towards the use of bow and arrow . Weapons . After the arrival of the Spanish , the Inca adopted European military technology such as horses , sword s , and armor . It is known that Manco Inca led an Inca cavalry unit against Spanish occupation forces . Forms of conquest . Peaceful conquest . Peaceful conquest was possible when a curaca agreed to recognize the Sapa Inca as their emperor in return for a number of benefits . These benefits could include gifts , investment in public works , recognition at their investiture , interchange of women to establish family ties etc . Whether submission was due to fear of the Inca army or genuine friendship the curaca became a beneficiary of the offered gifts , but he also became subject to Inca demands : his lands had to be handed over to the estate , he had to supply labour and soldiers etc . It was a conquest through reciprocity . Violent conquest . Violent conquest would occur if a tribe was too proud or warlike to accept the Sapa Inca as their emperor . This generally resulted in a bloody war and subsequent Inca victory . The conquered tribe would receive reprisals according to the length of the war . The defeated leader would be executed and , depending on the degree of their rebellion , the subjects would either be moved to a distant place or , in extreme cases , totally annihilated as a punishment to avoid future uprisings . History . Local phase ( 13th Century - 1438 ? ) . This phase lasted from the beginning of the Inca period until the end of the rule of Pachacuti ( or Pachacútec ) . During this phase the army was relatively small and weak . The only battles it fought were for reasons of defense or survival . On occasions the rulers also led the army into battle . There were frequent battles during this period against small tribes such as the Alcahuasis or the Canas . The Aymara or the powerful Chancas were greater threats and the Inca army had to confront them on a number of occasions . Imperial phase ( 1438 ? - 1532 ) . This period started with the defeat of the Chancas , with Pachacuti at the head of the Inca army . From this time on the Inca army would be a multiethnic army and it would be more sophisticated and numerous . The conquered ethnic groups rapidly became a part of the Inca nation and contributed men to its armies . During this period the majority of the wars involved the conquest of new territories and it was during this period that the army was at its most powerful . Invasion ( 1532 - 1572 ) . During this period the majority of the army was decimated by illness , Spanish attacks and rebellions . Initially the Inca soldiers feared the horses and firearms of the Spanish which reduced their fighting efficiency . However , they soon forgot their fears and some Inca battalions even fought with swords and Spanish weapons and as cavalry units . For the largest battles the Inca army was commanded by Quisquis and Manco Inca Yupanqui who was commander during the battle of Sacsayhuamán . At the end of this period the Inca army lost battles not just to the Spanish but also to subjected tribes that took advantage of the arrival of the Spanish .