Steiermark, Bundesland (federal state), southeastern and central Austria, bordering Slovenia on the south and bounded by Bundesländer Kärnten (Carinthia) on the south, Salzburg on the west, Oberösterreich and Niederösterreich (Upper and Lower Austria) on the north, and Burgenland on the east. It has an area of 6,327 square miles (16,387 square km). Upper Steiermark extends in the north from the Limestone Alps to the eastern groups of the Central Alps, embracing the valleys of the Mur, Mürz, Salza, and Upper Enns rivers. The Lower Steiermark upland and hill country consists of the middle Mur Valley with the Grazerfeld “plain” in the centre; the Koralpe and Packalpe rising above 6,500 feet (2,000 metres) in the west; and a gravel, loam-covered hill country in the east.
Inhabited since the Stone Age and mined as early as the Bronze Age, the region became part of the Celtic kingdom of Noricum, which was incorporated into the Roman Empire c. 15 bce. In the 5th century it was overrun by Germanic tribes, followed by the Avars and their Slav subjects (Slovenes). Subjected by the Bavarians in the 8th century, the country became a mark, or frontier territory, of the Frankish Empire. Further German colonization led to Germanization by c. 1300, except in the southern countryside. The area of modern Steiermark belonged to the duchy of Carinthia (Kärnten) after 976, but other northern areas of modern Steiermark were acquired in the 11th and 12th centuries by the counts, or margraves, of Traungau, whose main seat was at Styraburg, or modern Steyr (Oberösterreich). In 1180 the entire area became the duchy of Steiermark, or Styria, which passed to the Babenberg duke of Austria in 1192 until the extinction of the Babenberg line in 1246. In 1276 most of the area was ceded to the Habsburgs, and it became a crown land in 1282. Thereafter, its history was merged with that of Austria, although it was ruled only by junior branches of the House of Habsburg from 1379 to 1439 and from 1564 to 1619. After World War I, 2,329 square miles of southern Steiermark, including Marburg (Maribor), Cilli (Celje), and Pettau (Ptuj), were ceded to Yugoslavia. Steiermark has been a Bundesland ever since, except for the years 1938–45 when most of it formed a Reichsgau (party district) under the Anschluss, or incorporation into Germany.
Ethnically, Steiermark is German. Most inhabitants are Roman Catholic. Ancient folklore, song, and dance are preserved in the mountainous areas and the gray-green Steiermark suit is almost an Austrian national costume. The principal urban centres are Graz, the capital, Leoben, Kapfenberg, Bruck, Eisenerz, Knittelfeld, Köflach, Mürzzuschlag, and Fohnsdorf.
Steiermark’s economic development has always been determined by its mineral resources. The Erzberg near Eisenerz supplies most of Austria’s iron ore and has been mined since Celtic times. Brown coal (lignite) is mined at Fohnsdorf and Köflach and magnesite in the Shale Alps. The state also produces sizable amounts of graphite, talc, gypsum, and salt. Thermoelectricity is generated, and there are hydroelectric plants on the Mur and other rivers. Heavy industry is concentrated in the Mur Valley below Fohnsdorf and in the Mürz Valley. Metal and machine industries, sawmills, automobile development and production, and paper and cellulose industries are important; chemicals, textiles, leather, and food products are also manufactured. Major industrial sites are in Graz, Leoben, Bruck, and Kapfenberg. Agriculture employs a small percentage of the working population; livestock raising is widespread, and corn (maize) and fruit are cultivated in the southeast. There is a significant tourist trade, based on numerous mountain resorts. Pop. (2021) 1,251,683; (2023 est.) 1,269,801.