A very long time ago, Illyrian and Celtics tribes lived in Slovenia. In the 1st century BC, Slovenia was ruled by the Romans. In the sixth century AD, Slavs lived there. Slovenia was ruled by Austria from 1335 until 1918. In 1918 it became a part of Yugoslavia. During World War II, Italy, Hungary and Germany took parts of the country but in 1945 it became part of Yugoslavia again.