At its height, the Tarascan kingdom extended over a territory of approximately 75 000 km2 and was a major rival to the Aztec empire. According to the Relación de Michoacán, a document written about 1540 that was based on oral tradition, the Tarascan, or Purépecha, society was highly hierarchical. Its artisans were organized into guilds and a large part of what they produced was intended to honour deities or meet the needs of elites. Certain types of vessels, including stirrup-spout bottles, seem to have been reserved for people of high rank. Traces of cocoa found in many such bottles indicate they contained precious ingredients, sometimes imported from afar. The circulation of these bottles throughout the area also seems to have played a major role in the creation and maintenance of alliances among the elites.