Setting the Stage for Study of the Codex Borgia

Chapter 1 discusses where the Codex Borgia was created in Central Mexico and how it arrived in Europe. This chapter then examines the format of different almanacs in the Codex Borgia and parallels with other “Borgia Group” screenfold books and Aztec codices. A comparative study of Central Mexican calendars outlines the 260-day divination count and the 365-day year divided into 20-day veintenas. Chapter 1 also explains how different layouts of the 260-day divination count had different directional associations, as did the yearbearers naming the year in the 52-year cycle. The Calendar Round dates in a directional almanac on Borgia 49–52 divide the 52-year cycle into four sets of thirteen years, which establishes conceptual links between time and space. Calendar Round dates also set the Codex Borgia in historical context, which helps date the astronomical events portrayed in the codex.