The T and O map, which is short for the Orbis Terrarum map, was an early world map created in the medieval period. This map is also sometimes called the Beatus map because one of the earliest known drawings of this map was created by Beatus of Liebana, an 8th century monk who lived in Spain. The map first appeared in the prologue to his twelve volume commentary on the apocalypse.
Although Beatus made the earliest drawing of this map, the first description of this map came from 7th century scholar Isidore of Seville, who described the T and O map in the 14th chapter of his book Etymologiae. Isidore described the world in the following manner;
The [inhabited] mass of solid land is called round after the roundness of a circle, because it is like a wheel [...] Because of this, the Ocean flowing around it is contained in a circular limit, and it is divided in three parts, one part being called Asia, the second Europe, and the third Africa.
There is some debate as to whether Isidore meant that the world is round and flat or globular, especially since the theory of a spherical world was in existence at the time.
The continents of Asia, Africa and Europe are all visible on the map, as is the Nile, Don and Mediterranean Ocean. Jerusalem is marked on the map as the middle of the world.