A Greek traveller and geographer of the first half of the sixth century, b. at Alexandria, Egypt. Cosmas probably received only an elementary education, as he was intended for a mercantile life, and in his earlier years was engaged in business pursuits. It may be, however, that by further study he increased his knowledge, since his notes and observations show more than ordinary training. His business took him to the regions lying south of Egypt, the farthest point of his travels in this direction being Cape Guardafui. He traversed the Mediterranean, the Red Sea, and the Persian Gulf, and gathered information about lands lying far to the East; but it is not certain that he actually visited India. In his later years he entered the monastery of Raithu on the Peninsula of Sinai. If it be necessary to suppose, as some investigators assert, that Cosmas was at any time a Nestorian, it would appear from his work, the "Christian Topography", that, at least towards the close of his life, he returned to the orthodox faith. While an inmate of the monastery he wrote the "Topography" above mentioned, a work which gives him a position of importance among the geographers of the early Middle Ages.

The "Christian Topography" has been preserved in two manuscript copies, one in the Laurentian Library at Florence, and the other in the Vatican. In the second half of the seventeenth century Isaac Vossius, Emeric Bigot, and Melchisédech Thévenot first made the work known in a fragmentary way by publishing extracts from it. The first complete and critical edition, accompanied by a Latin translation, was issued by Bernard de Montfaucon in his "Collectio nova patrum et scriptorum græcorum (Paris, 1707), II, 113-345. The "Topography" was also printed by Galandi in his "Bibliotheca veterum patrum" (Venice, 1776), and in Migne, P.G. (Paris, 1864), LXXXVIII, 51-476. A French translation of the most important parts is found in Charton, "Voyageurs anciens et modernes" (Paris, 1855); a complete English translation, with notes and a critical introduction, was issued for the Hakluyt Society by J. W. McCrindle (London, 1897). The work is divided into twelve books and contains a description of the universe, as Cosmas constructed it in his imagination, and an account of those regions which he had visited, or concerning which he had gathered information. According to Cosmas the world is a rectangular structure in two sections, their length much greater than their breadth, and corresponding in form and proportions to the Tabernacle of the Old Testament. The base is formed by the surface of the earth, around which flows the ocean; on the other side of the ocean lies another - unknown - continent, from which rise the walls that support the firmament above. The stars are carried by the angels in a circle around the firmament. Above the firmament springs a vault which separates the heaven of the blessed from the world beneath. The theory that there is an antipodes, says Cosmas, is a doctrine to be rejected. The earth rises towards the north and ends in a cone-shaped mountain behind which the sun continues its wanderings during the night, and the nights are long or short according as the position of the sun is near the base or the summit of the mountain.

This curious attempt to harmonize a childish Biblical exegesis with ordinary phenomena and the current opinions of the time is at least superior to the extraordinary geographical hypotheses of that day. Aside from the fact that the theories of Cosmas exercised no influence, they are not of sufficient importance to affect the genuine worth of several portions of the "Topography". The value of these passages rests on the methodical conscientiousness of the simple merchant, as it is seen, for example, in the careful copy of the so-called Inscription of Adulis (Monumentum Adulitanum) which has been preserved to Greek epigraphy only in the copy of Cosmas. Cosmas, with the aid of his travelling companion, Menas, took a copy of it in 522 for the governor of the Christian king Elesbaan of Abyssinia, retaining a replica for himself. Of equal importance is the information he collected concerning Zanzibar and the Indian Ocean, and what he learned as to the trade of Abyssinia with the interior of Africa and of Egypt with the East. The best-known and most celebrated part of the "Topography" is the description, in the ninth book, of Ceylon and of the plants and animals of India. The work also gives much valuable information concerning the extension of Christianity in his day. The Vatican manuscript of the "Christian Topography" has explanatory maps and sketches, either made by Cosmas himself or prepared under his direction; they are of value as the first efforts of patristic geography. Four other writings of Cosmas are unfortunately lost: a cosmography, an astronomical treatise, and commentaries on the Canticles and the Psalms.

MARINELLI, La geografia e i padri della chiesa (Rome, 1883); GELZER, Kosmas der Indienfahrer in Jahrbuch für protestantische Theologie (Leipzig, 1883), IX, 105-141; KRETSCHMER, Die physische Erdkunde im christlichen Mittelalter (Vienna, 1889); BEAZLEY, The Dawn of Modern Geography (London, 1897); KRUMBACHER, Gesch. der byzantinischen Litt. (2nd ed., Munich, 1897), 412-14; STRZYGOWSKI, Der Bilderkreis des griech. Phnysiologus, des Kosmas Indicopleustes, etc., in Byzantinisches Archiv (Leipzig, 1899).

OTTO HARTIG