Styria (), also Slovenian Styria (Slovenska Štajerska) or Lower Styria (Spodnja Štajerska; ), is a traditional region in northeastern Slovenia, comprising the southern third of the former Duchy of Styria. The population of Styria in its historical boundaries amounts to around 705,000 inhabitants, or 34.5% of the population of Slovenia. The largest city is Maribor. Use of the term In the 19th century the Styrian duchy, which existed as a distinct political-administrative entity from 1180 to 1918, used to be divided into three traditional regions: Upper Styria (Obersteiermark; Zgornja Štajerska), Central Styria (Mittelsteiermark; Srednja Štajerska), and Lower Styria, stretching from the Mur River and the Slovene Hills in the north down to the Sava. Upper Styria and Central Styria, predominantly German-speaking, today form the Austrian state of Styria (Steiermark). The southern third, predominantly Slovene-speaking Lower Styria, became part of the Kingdom of Serbs, Croats and Slovenes (Yugoslavia) after World War I. After World War II, it became part of the predecessor of modern Slovenia, the Socialist Republic of Slovenia. Although used interchangeably at times, the term "Southern Styria" (Südsteiermark) refers to the southern districts of the Austrian state of Styria, whereas the term "Lower Styria" (Spodnja Štajerska) refers to the region of Styria in northeastern Slovenia. The Slovene name Štajerska is borrowed and adapted from the German name for the region, Steiermark. History In the Middle Ages, the Lower Styrian lands were ruled by several immediate (reichsfrei) dynasties like the Counts of Celje, whose large possessions were not incorporated by the Habsburg dukes until the 15th century. According to the last Austro-Hungarian census of 1910, Lower Styria had around 498,000 inhabitants, of which around 82% were Slovene and around 18% German speakers. In 1918, after the disintegration of the Austro-Hungarian monarchy following World War I, the Duchy of Styria was divided between the newly established states of German Austria and the Yugoslav State of Slovenes, Croats and Serbs. In early November 1918, Rudolf Maister, a Slovene major of the former Austro-Hungarian Army, with about 4,000 local volunteers occupied Lower Styria and the town of Maribor and claimed it for Yugoslavia. After a short fight with German-Austrian paramilitary units, the current border was established, acknowledged by the provisional Styrian assembly at Graz. By December 1918, all of Lower Styria was de facto included in the Kingdom of Serbs, Croats, and Slovenes. A protest by German-speaking Marburg citizens resulted in the Marburg