Assyria, the northernmost of the three great countries that occupied the Mesopotamian plain. It was bounded on the N. by the Niphates Mountains of Armenia; on the S. by Susiana and Babylonia; on the E. by Media; and on the W., according to some, by the Tigris, but more correctly by the watershed of the Euphrates, for many Assyrian ruins are found to the west of the Tigris. It was thus about 280 miles long from N. to S., and rather more than 150 broad from E. to W. This plain is diversified by mountain-chains on the north and east, and watered by the Tigris and its affluents, between two of which - the Zab rivers - lay the finest part of the country, called Adiabene. As it was the boundary-land between the Semitic people and Iran, it became the scene of important political events. Its extraordinary fertility enabled it to support a large population. The high degree of prosperity and civilisation reached by its inhabitants in very early times is attested not only by ancient writers, but by the extensive ruins of mighty cities, by the canals and contrivances for irrigation, and by the numerous proofs - furnished by recent excavations - of an acquaintance with the arts and sciences. The ruins of many cities are grouped around Nineveh; while lower down, the Tigris exhibits an almost unbroken line of ruins from Tekrit to Bagdad. Under the Mohammedans this fine country is now almost a desert. Nineveh (q.v.) was the capital. There are indications that this Semitic state was founded as far back as 2330 b.c.; its king was certainly powerful about 1320 b.c.; Tiglath-pileser (1140) was its first great prince; after some centuries of decay the empire was again a great power under Shalmaneser II, (85S). In the 7th century b.c. the empire was greatly decayed, and Babylon independent: finally Nineveh was taken in 605, and Assyria became a province of Media. The Assyrian language was akin to Hebrew and Phoenician. On the topography and archaeology, see books by Botta, Oppert, Layard, George Smith, Perrot and Chipiez, Sayce, Maspero, Rogers (1901).