Approximately 1100
mappae mundi (maps of the world) have survived from the Middle Ages; about 200 are separate maps; the rest are in books.
Maps of the world were obviously limited by knowledge of geography. This did not deter medieval cartographers, however, since maps existed for along time not as guides for travelers, but as diagrams of the layout of God's creation. Minutiae weren't as important as portraying the overall plan, or showing a particular feature. For instance, Gervase of Canterbury's
Mappa Mundi was drawn up specifically to show the bishopric s and ecllesiastical foundations of England, Scotland and Wales.
One of the most common of the map designs was the T-O design, called that by modern scholars because it resembled those letters. The "T" was the division of the major landmasses with the enormous Asia topping Europe and Africa; "O" was the encircling Ocean.
Note that Asia is on top. When choosing proper positioning for the arrangements of the continents, the direction of the rising sun seemed to be a logical place to begin. East is therefore placed at the top of the maps, and the arrangement of things in their proper place on a map therefore was called "orienting."*
Cicero's
Dream of Scipio (in which a vision of the world is viewed in detail) was very popular in the Middle Ages for what it had to say about the world and the divine. Macrobius' (5th century CE)
Commentary on it was how many readers became familiar with it. Many copies of the
Commentary include
mappa mundi of the type therefore called Macrobian. The
Dream includes a description of the various zones, cold to temperate to hot to temperate to cold. Only the temperate zones were considered habitable.
Fourteen manuscripts of Beatus of Liébana's (c.730-800) popular
Commentary on the Apocalypse of St. John include the quadripartite-style map that squeezes the
Antipodes into the extreme south.
The most famous and most detailed maps provide the most variety and data and start to approach the realism and usefulness of modern cartography. The symbolic value of the
mappae mundi began to be replaced by the need for accurate information to aid in travel and, especially, navigation on the seas. The new "Portolan Charts" became far more valuable to have and reproduce, and the number of
mappa mundi were produced less.
If you would like to see some maps from across the ages, a good start is the
Imaginary Museum.
*
An extra tidbit: "orient" comes to Middle English from Latin via French and the verb oriri, "to rise"; once in English it starts being used for the direction itself in which the sun rises.