Slavonia has been settled since the earliest age of prehistory which is confirmed by the finding sites of Neanderthal man and early paleolithic and neolithic cultures. In history, a deep mark was left by the Illyrians and Celts, and in the 1st century BC, it falls under Roman authority. After the fall of Western Roman Empire, under whose authority it was, the great migration period happens on its territory. In the 7th century, the Croats came and found their principalities. The name Slavonia comes from middle age latin name S(c)lavonia which means „a land inhabited by Slavs“. In the beginning, this area was under the domination of Kingdom of the Franks, but it became independent and a part of Kingdom of Croatia in the 10th century. Since the 12th century it was a part of Croatian union with Hungary and since the 16th century, it was a part of Habsburg Monarchy. It was extremely important in the wars against the Ottoman Empire. In the 19th century, the idea of national consciousness began and in the 20th century, after World War II, it linked with other Croatian lands. With the establishment of Republic of Croatia, it became one of its main parts, but a few years would still pass before it was completely defended in the Croatian War of Independence.