AUSTRIA-HUNGARY. Under this heading an account is given of the history of those territories in central and eastern Europe, since 1918 partitioned among Italy, Austria, Czechoslo vakia, Poland, Hungary, Rumania and Yugoslavia, which were accumulated by the dynasties of Babenberg and Habsburg round the nucleus of the "Ostmark" established in A.D. 976. The genera tion which saw the dissolution of this empire in 1918 knew it as "Austria-Hungary"; but this title was of recent date, and rep resented (and inadequately) only one phase of this venerable but singularly unstable organism. To call the whole "Austria" is admittedly inexact ; but an exact definition of the term is equiv alent to an examination of its whole history. The word repre sents, at any rate, the spiritual idea of an eastern bulwark and defence of the German nation and of Christendom itself, in which Austria lived. In proportion as it became untrue to this task, or as the need for it disappeared, Austria withered, and at last per ished. The following article will describe the rise of the original Ostmark and its development into a European power of the first magnitude, together with the international or internal events affecting the countries which at various times composed the Aus trian empire as a whole ; the internal histories of these countries being given under the appropriate headings (see HUNGARY,