Isidore of Seville drew largely from Orosius in writing his chapters on geography. Theoretically he accepted the tripartite division,[1185] but in his actual treatment of the countries of the world he appended a discussion of islands to his discussion of the continents. In this he was followed by the author of the _De imagine mundi_ and by many other writers of the time,[1186] all of whom declared that the earth’s surface is divided in three, but added chapters on the islands after their descriptions of Asia, Africa, and Europe. _THE CENTER OF THE “OIKOUMENE”_ JERUSALEM AS THE CENTER During the Middle Ages the idea that Jerusalem is at the center of the _oikoumene_ seems gradually to have gained ground. Arculf, a bishop of an unknown see in Gaul and pilgrim to the Holy Land, so described it as early as the close of the seventh century;[1187] but the tradition does not appear to have become established in the cartography of the West until the twelfth or even the thirteenth century.[1188] To place Jerusalem at the center was to recognize the preëminence given that city in Scripture, not only in the New but also in the Old Testament.[1189] It is natural for primitive peoples to think that the most holy of all places occupies a central position:[1190] the Greeks believed that either Delphi or Olympus was the navel of the earth;[1191] the Scandinavians thought the same was true of Asgard; the Hindus, of Mount Meru; the Babylonians, of Nippur.[1192] Gervase of Tilbury argues in a confused, semi-theological manner on the position of Jerusalem:[1193] Augustus, he believed, had thought that Judea was the heart of the earth because that Emperor had begun a survey of the provinces of the empire there; in addition, from texts of the Bible Gervase attempted to demonstrate that Jerusalem is halfway between the North and the South, that by “antithesis” it must be halfway between the East and the West, and consequently must be at the center of the known world. THE EXACT POSITION OF THE EARTH’S CENTER There seems to have existed in the minds of writers some confusion as to the exact spot that marks the navel of the earth. A map of the year 1110 identifies it with Mount Zion.[1194] The pilgrim Saewulf, who was in the Holy Land in 1102 and 1103, says:[1195] “At the head of the Church of the Holy Sepulchre, in the wall outside, not far from the place called Calvary, is the place called Compas, which our Lord Jesus Christ himself signified and measured with his own hand as the middle of the world, according to the words of the Psalmist, ‘For God is my king of old, working salvation in the midst of the earth.’ But some say that this is the place where our Lord Jesus Christ first appeared to Mary Magdalene, while she sought him weeping and thought he had been a gardener, as is related in the Gospels” (Thomas Wright’s translation).[1196]