Astrology is the art of predicting events on earth as well as human character and disposition from the movements of the planets and fixed stars. Medieval astrology encompassed both general concepts of celestial influence, and the technical art of making predictions with horoscopes, symbolic maps of the heavens at particular moments and places constructed from astronomical information. The scientific foundations of the art were developed in ancient Greece, largely lost in early medieval Europe and recovered by the Latin West from Arabic sources in the 12th and 13th centuries. Late medieval astrological images were successfully Christianized and were adapted to particular contexts, acquired local meanings and changed over time....
The medieval term mappa mundi (also forma mundi, historia/istoire) covers a broad array of maps of the world of which roughly 1100 survive. These have resisted systematic classification, but the clearly dominant type is one that aims at comprehensively symbolistic representation. Its early, schematic form is a disc composed of three continents surrounded and separated from one another by water (“T-O Map”) and associated with the three sons of Noah: Asia (Shem) occupies all of the upper half, Europe (Japhet) to the left and Africa (Ham) to the right share the lower half. Quadripartite cartographic schemes included the antipodes as a fourth continent, but the tripartite model was adopted by the large majority of the more developed world maps in use from the 11th century on and—with important variations—well into the Renaissance. While details were added as available space permitted, the Mediterranean continued to serve as the vertical axis and, with diminishing clarity, the rivers Don and Nile as the horizontal one. The map also continues to be ‘oriented’ towards Asia, where paradise sits at the very top. A circular ocean forms the perimeter and not infrequently the city of Jerusalem constitutes its centre....
C. A. Keller
c. 1290–c. 1279