COS or STANKO, an island not far from the south-western corner of Asia Minor, off the Gulf of Ceramus. Its total length is about 25 m. Its population is nearly all Greek, with Turks also, and Greek-speaking Mohammedans from Crete in the capital. The island consists of three regions, an abrupt limestone ridge (anc. Prion, "the saw" from its jagged profile) along the eastern half of the south coast, a rugged peninsula (Kephala) at the west end, and a central lowland of fertile marls prolonged along the north coast to the ancient capital facing the mainland. Along the north slope of the Prion ridge copious deep-seated springs provide water for the town and for extensive irrigation. The Cos lettuce is well known. The principal resources of Cos are its vineyards, figs and olives ; wheat, barley and maize are grown, though a considerable proportion of the arable land is left untouched. Melons, grapes and other summer fruits are exported in large quantities to Egypt, mostly in local sailing boats. Cotton, tobacco, sesame and silk are grown in small quantities.
The mediaeval harbour is fit only for quite small vessels, but the roadstead is safe in most weathers and steamers call here. The ancient and mediaeval town round the harbour has a well preserved fortress, founded by the Knights of Rhodes : in its walls are interesting architectural fragments. The famous plane-tree in the market-square has a circumference of about 3o ft., and its huge branches have to be supported by pillars. Of its age there is no certain knowledge; the popular tradition connects it with Hippocrates. The town is supplied by an aqueduct, about 4 m. in length from the fine ancient wellhouse of Borinna high on Mt. Prion. The village of Pyli has the fine Greek tomb of Charmylos, and at Kephala is an outlying castle of the knights of St. John : numerous inscriptions prove that it occupies the site of the ancient township of Isthmos. The prosperous village of Antimachia is the corn-market of the central lowland. The precinct of Asclepius (excavated in 190o-1904) about 2 m. from the town of Cos, con sists of three terraces, containing temples, an altar, porticoes and other buildings and a medicinal spring; below is a large enclosure with porticoes. The earliest buildings on the middle terrace date from the 6th century B.C. The temple on the upper terrace, with an imposing flight of steps, is of the 2nd century B.C. After a destructive earthquake, the whole site was remodelled by Xeno phon, the physician who poisoned the emperor Claudius. The sanctuary was desolated by the earthquake of A.D. 554.
History.—Cos was settled by Dorian colonists from Epidaurus who worshipped Asclepius, whose sanctuary became a health-resort and the first school of scientific medicine. In the 5th century it joined the Delian League. Usually its government was aristo cratic, but in 366 a democracy was instituted. In 357-355 it resisted Athenian aggression ; then fell for a few years into the power of Mausolus, prince of Halicarnassus. In the Hellenistic age Cos owed its prosperity to the friendship of the Greek dynasty of Egypt, who valued it as a naval outpost. As a seat of learning it was adopted for the education of Ptolemaic princes ; amongst its most famous men were the physician Hippocrates, the painter Apelles, the poets Philetas and Theocritus (q.v.) . Like its neigh bour Rhodes, Cos generally supported the Romans. In A.D. 53 it was made a free city. In A.D. 1315 it was occupied by the Knights of St. John, its castle, with that at Halicarnassus (Budrum) serv ing as outer-guard to Rhodes; in 1523 it passed under Ottoman sway and in 1912 was occupied by Italy during the Tripoli war. The full sovereignty of Cos and other Aegean islands was formally ceded to Italy by Turkey in the Treaty of Lausanne, 1924.
BIBLIOGRAPHY.—L. Ross, Reisen nach Kos, etc. (Halle, 1852), pp. Bibliography.—L. Ross, Reisen nach Kos, etc. (Halle, 1852), pp. 91-29, and Reisen auf den griechischen I M reln (Stuttgart, 184o-45) , ii. 86 ff.; 0. Rayet, Memoire sur file de Cos (Paris, 1876) ; M. Dubois, De Co Insula (Paris and Nancy, 1884) ; W. Paton and E. Hicks, The Inscriptions of Cos (Oxford, 1891) ; B. V. Head, Historia Numorum (Oxford, pp. ; Archaol. Anzeiger, 1g05, i.