Indian auxiliaries, also known in the sources asIndios amigos (lit. 'friendly Indians'), were thoseIndigenous peoples of the Americas who allied withSpain and fought alongside theconquistadors during theSpanish colonization of the Americas. These auxiliaries acted as guides, translators, soldiers, explorers and porters, often outnumbering peninsular Spaniards by enormous degrees in their military formations. During theSpanish conquest of the Inca Empire, Indigenous assistants were referred to by the Indigenous word ofyanakuna.

Indian auxiliaries continued to be used by the Spanish to maintain control over their colonies in the Americas; frequently stationed on thefrontier, they were often used to suppress anti-colonial revolts such asArauco War. Their important role in achieving the conquests of Spain gave birth to a modern Spanish-speaking idiom,la conquista la hicieron los indios ("the Indians did the conquest").^[1]

The formations of auxiliary Indians arose commonly from alliances established by theSpaniards, exploiting ethnic and tribal antagonisms that they found during their occupation of the territory they were attempting to conquer.Vasco Núñez de Balboa andHernán Cortés were among the first captains to strengthen their columns with these natives.

DuringHernán Cortés' campaign against the Aztecs from 1519 to 1521, he supplemented his meagre force of Spanish soldiers (numbering some 1,300) with hundreds of thousands of native auxiliaries, from various states such asTlaxcala,Texcoco andCholula. They were commanded byChichimecatecuhtli andIxtlilxochitl II from their respective factions.

During the final siege of the Aztec capital city ofTenochtitlan, Cortés, according to the account of one of his soldiers,Bernal Díaz del Castillo, had some 200,000 Tlaxcalan and other native auxiliaries, while the Aztec warriors drawn from the numerous cities surroundingLake Xochimilco in theValley of Mexico numbered more than 300,000.

The expedition ofPedro de Alvarado toGuatemala was composed of 480 Spaniards and thousands of auxiliary Indians fromTlaxcala,Cholula and other cities in central Mexico.^[2] In Guatemala the Spanish routinely fielded Indigenous allies; at first these wereNahua brought from the recently conquered Mexico, later they also includedMaya. It is estimated that for every Spaniard on the field of battle, there were at least 10 native auxiliaries. Sometimes there were as many as 30 Indigenous warriors for every Spaniard, and it was the participation of these Mesoamerican allies that was particularly decisive.^[3] Some newly conquered Maya groups remained loyal to the Spanish once they had submitted to the conquest, such as theTz'utujil and theK'iche' ofQuetzaltenango, and provided them with warriors to assist further conquest.^[4]

In 1524, fresh from his victory over the Tz'utujil, Pedro de Alvarado led his army against the non-MayaXinca of the Guatemalan Pacific lowlands.^[5] At this point Alvarado's force consisted of 250 Spanish infantry accompanied by 6,000 Indigenous allies, mostlyKaqchikel and Cholutec.^[6]

TheMam fortress ofZaculeu was attacked byGonzalo de Alvarado y Contreras, brother of Pedro de Alvarado,^[7] in 1525, with 40 Spanish cavalry and 80 Spanish infantry,^[8] and some 2,000 Mexican and K'iche' allies.^[9] When the Spanish besieged theIxil city ofNebaj in 1530, their Indigenous allies managed to scale the walls, penetrate the stronghold and set it on fire. Many defending Ixil warriors withdrew to fight the fire, which allowed the Spanish to storm the entrance and break the defences.^[10]

• During thesiege of Cuzco,Francisco Pizarro had 200 Spaniards and 30,000 nativeChankas,Huancas,Cañaris andChachapoyas. The native contingents were commanded by chieftainsChilche andVilchumlay, among others.
• The column ofDiego de Almagro, who went intoChile, had 500 Spaniards, 100 African slaves and about 10,000 auxiliary Indians.
• In the case of theconquest of Chile byPedro de Valdivia, the original group who left Cuzco included 11 Spaniards and 1,000 auxiliary Indians.

• TheTlaxcaltecs accompaniedMiguel López de Legazpi to the conquest of the Philippine Islands (part of the crew was Tlaxcaltec), where they settled and mixed with theTagalog indigenous society.^[11][12][13]

After the initial conquest, most of these allies were considered less necessary and, sometimes, a liability. At times they were needed for defense of the extendedSpanish Empire. They were incorporated into the military forces of the Empire, forming their own units, organised along European models under their own names, such asCompañías de Indios Nobles ("Companies of Noble Indians"). The necessity of defence came from either European threats like the Caribbean buccaneers and pirates or American threats such as theChichimeca,Apache orComanche tribes or the protractedArauco War. These units fought in the independence wars.^{[14][page needed]}

• United States Army Indian Scouts
• Sepoy
• Imbangala
• Indios reyunos
• Inca army
• Aztec warfare
• Malinchism
• Hispanics in the Roman army

• Indigenous military personnel of the Americas
• Spanish conquests in the Americas
• Conquistadors
• History of Indigenous peoples of the Americas
• Military history of the Caribbean
• Military history of Central America
• Military history of South America
• Military history of Latin America
• Military history of the Philippines
• Mesoamerican warfare

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