In October 1918, the Slovenes co-founded the State of Slovenes, Croats, and Serbs. Its territory has been part of many different states: the Roman Empire, the Byzantine Empire, the Carolingian Empire, the Holy Roman Empire, the Kingdom of Hungary, the Republic of Venice, the Illyrian Provinces of Napoleon's First French Empire, the Austrian Empire, and the Austro-Hungarian Empire. Slovenia has historically been the crossroads of Slavic, Germanic, and Romance languages and cultures. The capital and largest city- Ljubljana-is nearly the centre of the country. Continental climate is more pronounced towards the northeastern Pannonian Plain. The Julian Alps in the northwest have an alpine climate. A sub-mediterranean climate reaches to the northern extensions of the Dinaric Alps that traverse the country in a northwest–southeast direction. Slovenia has a predominantly continental climate, with the exception of the Slovene Littoral and the Julian Alps. Slovene, a South Slavic language, is the official language. Slovenes constitute over 80% of the country's population. Slovenia is mostly mountainous and forested, covers 20,271 square kilometres (7,827 sq mi), and has a population of 2.1 million (2,108,708 people). It is bordered by Italy to the west, Austria to the north, Hungary to the northeast, Croatia to the southeast, and the Adriatic Sea to the southwest.
^ Hungarian and Italian are co-official in some municipalities.