() is a term which means "lineage" in Spanish and Portuguese and has historically been used as a racial and social identifier. From the outset, colonial Spanish America resulted in widespread intermarriage: unions of Spaniards (), Amerindians (), and black Africans (). Basic mixed-race categories that appeared in official colonial documentation were , generally offspring of a Spaniard and an Indian; and , offspring of a Spaniard and a black African.

A plethora of terms were used for people with mixed Spanish, Indian, and African ancestry in 18th-century casta paintings, but they are not known to have been widely used officially or unofficially in the Spanish Empire.

Etymology is an Iberian word (existing in Spanish, Portuguese and other Iberian languages since the Middle Ages), meaning 'lineage'. It was first documented in Spanish in 1417 and is linked to the Proto-Indo-European . The Portuguese gave rise to the English word caste during the early modern period."Caste", Merriam-Webster's Collegiate Dictionary, 10th edition. (Springfield, 1999.)"Caste", New Oxford American Dictionary, 2nd edition. (Oxford, 2005).

Use of Casta terminology In the historical literature, how racial distinction, hierarchy, and social status functioned over time in colonial Spanish America has been an evolving and contested discussion.Vinson, Ben III. Before Mestizaje: The Frontiers of Race and Caste in Colonial Mexico. New York: Cambridge University Press 2018. Although the term (system of castes) or ("society of castes") are utilized in modern historical analyses to describe the social hierarchy based on race, with Spaniards at the apex, archival research shows that there is not a rigid "system" with fixed places for individuals.

The racial system was a more fluid social structure where individuals could move from one category to another, or maintain or be given different labels depending on the context. In the 18th century, "casta paintings", imply a fixed racial hierarchy, but this genre may well have been an attempt to bring order into a system that was more fluid. "For colonial elites, casta paintings might well have been an attempt to fix in place rigid divisions based on race, even as they were disappearing in social reality."

In New Spain (the colonial territory that is now Mexico and Central America) during the Mexican War of Independence, race and racial distinctions were an important issue and the end of imperial rule had strong appeal. José María Morelos, who was registered as a Spaniard in his baptismal records, called for the abolition of the formal distinctions the imperial regime made between racial groups, advocating for "calling them one and all Americans."quoted in Enrique Krauze, Mexico: Biography of Power. New York: HarperCollins 1997, p. 112 Morelos issued regulations in 1810 to prevent ethnic-based disturbances. "He who raises his voice should be immediately punished." In 1821 race was an issue in the negotiations resulting in the Plan of Iguala.quoted in Krauze, Mexico, p. 111.

"Colonial Caste System" debate The degree to which racial category labels had legal and social consequences has been subject to academic debate since the idea of a "caste system" was first developed by Polish-Venezuelan philologist Ángel Rosenblat and Mexican anthropologist Gonzalo Aguirre Beltrán in the 1940s. Both authors popularized the notion that racial status was the key organizing principle of Spanish colonial rule, a theory which became commonplace in the anglosphere during the latter half of the 20th century. However, recent academic studies in Latin America have widely challenged this notion, considering it a flawed and ideologically biased reinterpretation of the colonial period, as follows.

Pilar Gonzalbo, in her 2013 study discards the idea of the existence of a "caste system" or a "caste society" in New Spain, understood as a "social organization based on the race and supported by coercive power".Gonzalbo Aizpuru, Pilar, "La trampa de las castas" in Alberro, Solange and Gonzalbo Aizpuru, Pilar, La sociedad novohispana. Estereotipos y realidades, México, El Colegio de México, 2013, p. 15–193. She also affirms in her work that certain subliminal and derogatory messages in caste paintings were not a general phenomenon, and that they only began to be carried out in particular environments of the Criollo oligarchies after the Bourbon Reformism and the influx of ideas of scientific racism from the illustration within some encyclopedic environments of the colonial bourgeoisie.

Joanne Rappaport, in her 2014 book on colonial New Granada, The Disappearing Mestizo, rejects the caste system as an interpretative framework for that time, discussing both the legitimacy of a model valid for the entire colonial world and the usual association between "caste" and "race".

Similarly, Berta Ares' 2015 study on the Viceroyalty of Peru, notes that the term "casta" was barely used by colonial authorities which, according to her, casts doubt on the existence of a "caste system". Even by the 18th century, its use was rare and appeared in its plural form, "castas", characterized by its ambiguous meaning. The word did not specifically refer to sectors of the population who were of mixed race, but also included both Spaniards and Indians of lower socio-economic extraction, often used together with other terms such as plebe, vulgo, naciones, clases, calidades, otras gentes, etc.Ares, Berta, "Usos y abusos del concepto de casta en el Perú colonial", ponencia presentada en el Congreso Internacional INTERINDI 2015. Categorías e indigenismo en América Latina, EEHA-CSIC, Sevilla, 10 de noviembre de 2015. Citado con la autorización de la autora.

Ben Vinson, in a 2018 study of the historical archives of Mexico, addressing the issue of racial diversity in Mexico and its relationship with imperial Spain, ratified these conclusions.

Often called the or the , there was no fixed system of classification for individuals, as careful archival research has shown. There was considerable fluidity in society, with the same individuals being identified by different categories simultaneously or over time. Individuals self-identified by particular terms, often to shift their status from one category to another to their advantage. For example, both and Spaniards were exempt from tribute obligations, but were both equally subject to the Inquisition. , on the other hand, paid tribute yet were exempt from the Inquisition. In certain cases, a might try to "pass" as an to escape the Inquisition. An might try to pass as a to escape tribute obligations.

Casta paintings produced largely in 18th-century Mexico have influenced modern understandings of race in Spanish America, a concept which began infiltrating Bourbon Spain from France and Northern Europe during this time. They purport to show a fixed "system" of racial hierarchy which has been disputed by modern academia. These paintings should be evaluated as the production by elites in New Spain for an elite viewership in both Spanish territories and abroad portrayals of mixtures of Spaniards with other ethnicities, some of which have been interpreted as being pejorative in nature or seeking social outrage. They are thus useful for understanding elites and their attitudes toward non-elites, and quite valuable as illustrations of aspects of material culture in the late colonial era.

The process of mixing ancestries by the union of people of different races is known in the modern era as ( , ). In Spanish colonial law, mixed-race castas were classified as part of the and not the , which set Indians outside the Hispanic sphere with different duties and rights to those of Spaniards and Mestizos.

The caste system for these historians would have been misconstrued as being analogous to the castes of India. Given that in viceregal Spanish America there was never a closed system based on birth rights, where the birth rate and, therefore, wealth, created a "caste system" difficult to penetrate; but, rather, the statute of (a concept of religious root and not biological or racial) was given, in which the Indian and the mestizo, as a new Christian, had limitations on access to certain trades until assimilation full of his conversion to Catholicism; but that did not prevent his social ascent, and he would even receive protections that would benefit his social mobilization, protections that the old Christian of the would not enjoy (such as being free from all the taxes of the whites, with the exception of the Indian tribute, or be exempt from the Holy Inquisition). Then, those conceptions of a "caste society" or a "caste system" as characteristic of colonial society would be completely anachronistic formulations and could be part of the Spanish Black Legend. Given this, in works prior to those of Rosenblat and Beltrán, one would not find references to the notion that the Spanish empire was a society founded on racial segregation. Neither in Nicolás León, Gregorio Torres Quintero, Blanchard, nor in the Catalog of Herrera and Cicero (1895), nor in the article "Castas" of the Dictionary of History and Geography (1855), nor in Alexander von Humboldt's Political Essay on the Spanish-American territories that he visited on his scientific expeditions. Among other works that refer to the existence of castes and caste paintings, without implying connotations with modern racism, which would come to America after the French Enlightenment.

This would make these critics conclude that those colonial societies were rather of the class type, that although there was a relationship between class and race through castes, that was not in a cause relationship, but in a consequence relationship (not being an end in itself the race, which was understood in the Hispanic tradition as something purely spiritual, not so much biological). The purpose of the castas was to register the identity of lineages to register them in the republic of Spaniards, the republic of Indians, with the services and privileges acquired, which would not disturb the economic potential of the individual of the caste, nor would they have the purpose of to formally segregate them from positions of power, but to hierarchize them in feudal society (not equivalent to the same thing, as long as they were not prevented from ascending to the nobility or being part of the commercial petty bourgeoisie). Then, the viceroyalty society would be a society of "quality", estate, corporate, patronage and trade union, where each social group was not conditioned by their race, and neither did this establish the labor relations of its inhabitants. In the parish registers there would never have been the tendency to classify in so many innumerable mixtures as seen in the caste charts, which would be an artistic phenomenon typical of the Age of Enlightenment.Santiago Paúl Yépez