The Azcatitlan Codex narrates the story of the Aztec-Mexica, the indigenous population of Mexico. Its name derives from Aztlán, the name given to the original land of the Aztecs. It is composed of 25 folios written on European paper. Its date of creation is unknown, but some drawings are accompanied by calligraphy typical of the late 16th century.

The Codex is comprised of three distinct parts. The first part narrates the initial Aztec migrations and occupation of the promised land, México-Tenochtitlán. The history of the dynasty of the Tenochca monarchs, and the subsequent arrival of the Spaniards, is the subject of the second part. The third and last part tells the story of the conquest, from the first encounter between Hernán Cortés and the Emperor Moctezuma to the beginnings of the Colonial period.

The first known reference to this Codex appears in the catalog of the Indian historical museum of Lorenzo Boturini Benaduci (1702-1755). There are no documented references from the year 1791 onwards until 1830, when Joseph Marius Alexis Aubin (1802-1891), director of the École normale superièure de Paris, traveled to Mexico on a research trip and acquired the manuscript. In 1840 he returned to France with his library, and in 1889 he sold his collection to Eugene Goupil. Following Goupil's death, his wife donated the collection to the Bibliothèque Nationale in 1898.

The folio on display shows the march of the Spaniards toward Mexico in 1519. A flag depicts the Holy Spirit in the form of a dove. Spanish soldiers are dressed in armor, and behind them, Indians carry food. Cortés (with a beard but no hat) and Malinche (his interpreter) stand at far right. The manuscript is apparently missing one page, in which Moctezuma and his retinue would be facing Malinche.

The best-known depiction of indigenous traditions from central Mexico during the Colonial period is the Mendoza Codex, prepared on 71 folios of Spanish paper in Mexico City in ca. 1541 to acquaint the Emperor Charles V of Spain with his new colonial subjects. Mexico's first Spanish viceroy, Antonio de Mendoza, commissioned it in order to obtain a first-hand account of Aztec life while the last pre-conquest natives were still alive. Its compilation required teamwork. The hand of a single master painter is apparent throughout; his assistants prepared the pigments and applied color in flat washes. Informants who had lived most of their lives under Aztec rule interpreted the pictures in Nahuatl, and a Spanish priest then translated the text into Spanish. But alas, the Codex never reached Spain. The ship carrying it was captured by the French and all its booty taken to France. Years later an Englishman acquired it for 20 French crowns and took it to England, where it changed hands several times before entering Oxford University's Bodleian Library in 1659.

The Mendoza is in three parts: the first 19 folios narrate the history of the conquests of the Aztecs and the founding of Tenochtitlán, the next 37 folios enumerate the tributes received from the empire's 38 provinces, and the final 15 give an ethnographic account of public and everyday life. The first page depicts the founding of Tenochtitlán by the Aztecs in 1325. According to the mythical narrative, the Aztecs had originally lived as nomadic hunter-gatherers in the deserts of northern Mexico. They began migrating southward early in the 12th century, becoming the last in a series of cultures to arrive in the Valley of Mexico. The only place left for them to settle was an island, where they found the omen their god had promised: an eagle perched on a cactus growing out of a rock. This site inspired the glyph of Tenochtitlán, "Among the Stonecactus Fruit." With the addition of a snake in the eagle's mouth, this symbol now serves as Mexico's national emblem.

A small manuscript in the Vatican Library, bound in 16th-century crimson velvet, contains the earliest-known treatise on Mexican medicinal plants and native remedies. The Barberini is an herbal, documenting the pharmacological treatment of diseases. There were no Latin equivalents for most plant names, and so the translator had no choice but to record the Aztec names. Moreover, since the manuscript is illustrated, which in many cases is key to identifying the plants being described, it is a valuable source of Aztec lexicography. Each of its 13 chapters deals with a different group of afflictions, ranging from head to feet, stomach to bowels.

The Codex was the work of two Aztecs: Martinus de la Cruz, a native physician who wrote the manuscript in Nahuatl, and Johannes Badianus, who translated it into Latin. Both lived at the College of Santa Cruz in Tlaltelolco, one of the great cultural centers in the early period of Spanish colonization, and a place where liberal attitudes towards the Aztecs were practiced. The manuscript was intended as a gift to the Spanish Emperor Charles V. It found its way to Rome before the end of the 17th century, after which it remained in obscurity until 1929, when Charles Upson Clark discovered it in the Vatican Library and brought it to the attention of other scholars.