Carniola (Ger. Krain), a duchy and crown-land of Austria, bounded N. by Carinthia, N.E. by Styria, S.E. and S. by Croatia, and W. by Görz and Gradisca, Trieste and Istria. It has an area of 3856 sq. m. Carniola is for the most part a mountainous region, occupied in the N. by the Alps, and in the S. by the Karst (q.v.) or Carso Mountains. It is traversed by the Julian Alps, the Karawankas and the Steiner Alps, which belong all to the southern zone of the Eastern Alps. The highest point in the Julian Alps is formed by the three sugar-loaf peaks of the Triglav or Terglou (9394 ft.), which offers one of the finest views in the whole of the Alps, and which bears on its northern declivity the only glacier in the province. The Triglav is the dividing range between the Alps and the Karst Mountains, and its huge mass also forms the barrier between three races: the German, the Slavonic and the Italian. Other high peaks are the Mangart (8784 ft.) and the Jaluz (8708 ft.). The Karawankas, which form the boundary between Carinthia and Carniola, have as their highest peak the Stou or Stuhlberg (7344 ft.), and are traversed by the Loibl Pass (4492 ft.). They are continued by the Steiner or Santhaler Alps, which have as their highest peak the Grintouz or Grintovc (8393 ft.). This peak is situated on the threefold boundary of Carinthia, Carniola and Styria, and affords a magnificent view of the whole Alpine neighbouring region. The southern part of Carniola is occupied by the following divisions of the northern ramifications of the Karst Mountains: the Birnbaumer Wald with the highest peak, the Nanos (4275 ft.), and the Krainer Schneeberg (5890 ft.); the Hornwald with the highest peak, the Hornbüchl (3608 ft.), and the Uskokengebirge (3874 ft.). The portion of Carniola belonging to the Karst region presents a great number of caves, subterranean streams, funnels and similar phenomena. Amongst the best-known are the grottos of Adelsberg, the larger ones of Planina and the Kreuzberghöhle near Laas.
With the exception of the Idria and the Wippach, which as tributaries of the Isonzo belong to the basin of the Adriatic, Carniola belongs to the watershed of the Save. The Save or Sau rises within the duchy, and is formed by the junction at Radmannsdorf of its two head-streams the Wurzener Save and the Wocheiner Save. Its principal affluents are the Kanker and the Steiner Feistritz on the left, and the Zeyer or Sora, the Laibach and the Gurk on the right. The most remarkable of these rivers is the Laibach, which rises in the Karst region under the name of Poik, takes afterwards a subterranean course and traverses the Adelsberg grotto, and appears again on the surface near Planina under the name of Unz. Shortly after this it takes for the second time a subterranean course, to appear finally on the surface near Oberlaibach. The small torrent of Rothwein, which flows into the Wurzener Save, forms near Veldes the splendid series of cascades known as the Rothwein Fall. Amongst the principal lakes are the Wochein, the Weissenfels, the Veldes, and the seven small lakes of the Triglav; while in the Karst region lies the famous periodical lake of Zirknitz, known to the Romans as Lacus Lugens or Lugea Palus.
The climate is rather severe, and the southern part is exposed to the cold north-eastern wind, known as the Bora. The mean annual temperature at Laibach is 48.4° F., and the rainfall amounts to 72 ins. Of the total area only 14.8% is under cultivation, and the crops do not suffice for the needs of the province; forests occupy 44.4%, 17.2% are meadows, 15.7% are pastures, and 1.17% of the soil is covered by vineyards. Large quantities of flax are grown, while the timber trade is of considerable importance. Fish and game are plentiful, and the silkworm is bred in the warmer districts. The principal mining product is mercury, extracted at Idria, while iron and copper ore, zinc and coal are also found. The industry is not well developed, but the weaving of linen and lace is pursued as a household industry.
Carniola had in 1900 a population of 508,348, which corresponds to 132 inhabitants per sq. m. Nearly 95% were Slovenes and 5% Germans, while 99% of the population belonged to the Roman Catholic Church. The local diet, of which the bishop of Laibach is a member ex officio, is composed of thirty-seven members, and Carniola sends eleven deputies to the Reichsrat at Vienna. For administrative purposes the province is divided into eleven districts and one autonomous municipality, Laibach (pop. 36,547), the capital. Other important places are Oberlaibach (5882), Idria (5772), Gurkfeld (5294), Zirknitz (5266), Adelsberg (3636), Neumarktl (2626), Krainburg (2484) and Gottschee (2421).
Carniola derives its modern name from the Slavonic word Krajina (frontier). During the Roman Empire it formed part of Noricum and Pannonia. The Slavonic population settled here during the end of the 6th and the beginning of the 7th century. Conquered by Charlemagne, the most of the district was bestowed on the duke of Friuli; but in the 10th century the title of margrave of Carniola began to be borne by a family resident in the castle of Kieselberg near Krainburg. Various parts of the present territory were, however, held by other lords, such as the duke of Carinthia and the bishop of Freising. Towards the close of the 14th century all the separate portions had come by inheritance or bequest into the hands of Rudolph IV. of Austria, who took the title of duke of Carniola; and since then the duchy has remained a part of the Austrian possessions, except during the short period from 1809 to 1813, when it was incorporated with the French Illyrian Provinces. In 1849 it became a separate crown-land.
See Dimitz, Geschichte Krains von der ältesten Zeit his 1813 (4 vols., Laibach, 1874-1876).