Aztec histories have several formats. Res gestae histories read similarly to how one might read a picture book, with a succession of events pulling time forward. Only significant events move the story forward. Cartographic histories, generally standing alone as maps, show “the movement of people through legendary space and time.”[i] Maps show that events are tied to significant locations, and are especially helpful for showing migrations, for it is understood that as people are shown to move from place to place time is also passing. It is more difficult, however, to show a long period of geographical stability, which is why it is unlikely to see an imperial history in a cartographic account. Both of these formats are strong ways to indicate migration and conquest, which are important aspects of Aztec histories. The Aztecs start generally with the legendary and historic migration out of Aztlan. For the Aztecs, their identity as descendants of those who left Aztlan was very important to their qualities as leaders and as a populous. Lineage from Toltec civilizations was also important, but was often shown through integrated iconographic references to the Toltec, while the connection to Aztlan was always part of the narrative format.[ii]
Finally, there is the format of annals, in which time is the definitive factor, and which is the format of many surviving histories. In annals, much like a modern timeline, the years of the Aztec calendar continue in a relatively steady and linear fashion, and events are placed above, below, or next to the year in which they occurred. Each year is represented, regardless of the relative eventfulness of the year, although some years will have more depicted events than others. Because time is the constant, location is not as easy to depict, and so events like wars and migrations are signaled iconographically through footprints and place-signs. In most annals, events are fairly standardized in size, and so the relative importance of events is unclear. Events that are usually present include deaths and successions of rulers, ends/beginnings of 52 year cycles, large scale building projects, conquests, natural disasters, and celebrations. Some annals go into greater depth than others, with the Aubin being one of the more succinct annals, featuring less pictorial elaboration. Annals would typically follow a single strip, but in many that are made in European style books, such as the Aubin, the years are broken up and may read from top to bottom, side to side, or around the border of the page. Sometimes the established pattern of the year count will be broken or clustered to emphasize a certain event, such as the years of a ruler’s reign being together in a strip, and in this way the timeline itself carries narrative significance.
The imperial segment of the Codex Aubin contains short strips of years that read top to bottom, since it is on European paper, and the years are fairly spaced out so that there is more room for events (and the descriptive gloss written in Nahuatl). The grouping of year counts in annals to show a ruler’s reign is similar perhaps to the western concept of defining “periods” in history, however, these distinct sets of years are only there to show how long a ruler reigned and what occurred during his reign, rather than trying to show a greater cultural pattern within a certain set of years.
Annals, since they are primarily concerned with the constant of time, also make it difficult to show migrations, which are a primary concern for Aztec histories. Migrations integrate different historical structures, as Elizabeth Boone explains. Clusters of years followed by a place sign show that a certain number of years spent in residence at a specific location. This fuses the annals format with the res gestae format, allowing events to move the timeline forward more so than the year count, however, the year count is still present and so this emphasizes the continuity of time. All of the remaining Aztec annals depict the migratory period and/or the imperial period after the founding of Tenochtitlan. After the migration comes to a close with the founding, the imperial section of the manuscript begins. Additionally, in the Aubin, there is a section that is a listing of rulers accompanied by blue disks that tell how long they reigned. This list is somewhat of a res gestae element, showing the sense of moving from event to event, blended into an annal-like format, since it is a listing of rulers and so it is the same event repeated again and again.[iii]
Because of the use of res gestae along with the annals format, the migration section of the histories can be read like a story. Because it is so far in the past and because of the legendary aspects to the migration, it can be constructed as an arc of narrative with a beginning, middle, and end, unlike the annals of the imperial section which show time as continuing indefinitely.[iv] The whole of the annals is told from the perspective of the Mexica people and for the use of the Mexica, which is why the focus is so narrowly on Tenochtitlan’s founding and expansion. The melding of picture writing accompanied by Nahuatl writing also shows that the intention of these post-conquest annals was to chronicle the history of a civilization from its nascency to the colonial period of rapid changes, leaving a record of their culture in its most idealized form.