of Croatia in the Early Middle Ages. which later became part of the Kingdom of Croatia under Tomislav I Archaeological data show that cemeteries of northwestern Bosnia clearly indicate that from the first half of the 10th century this territory was under political rule of the Croatian ruler. Northern parts of the territories were part of Slavonian Banate (parishes Sana, Vrbas and Dubica, and Lower Pounje was part of Zagreb parish) as lower S(c)lavonia, where parish Sana served as seat of Babonić family (later Blagajski), and southern were parts of Pset and Pliva parish. In the 13th and 14th century, from Pliva parish, a region called Donji Kraji, located in today's southern Bosanska Krajina developed, and was first mentioned as a property of the Diocese of Bosnia and claimed by the Bosnian Banate. By the 14th century, the Ottoman Empire had significantly expanded into the western Balkans in a series of wars, and the Turkish westward incursions eventually made this region an Ottoman borderland. Jajce had fallen to the Ottomans in 1463, marking the downfall of the Kingdom of Bosnia, although was later taken from the Ottomans and organized as defensive Banate of Jajce. The Battle of Krbava Field in 1493 effectively ended the Kingdom of Hungary's persistent hold over the entire region, restricting them to fortified cities, and when Jajce fell again in 1528, Ottoman rule persisted almost till the end of 19th. century. In the late 15th century, a local Croatian lord (knez) Juraj Mikuličić erected a fort in the village of Bužim near Bihać, fearing the advancing Ottoman army. Mikuličić died in 1495, but the Bužim fort would not pass to Ottoman control until 1576. Bosanska Krajina was the last Region in Bosnia to fall to the Ottoman Empire, the last city to fall was Bihać in 1592. Ottoman period After the crucial 1526 Battle of Mohács and the 1527 election in Cetin, Croatia became part of the Austrian Habsburg Empire. The Ottoman Empire formally established the Eyalet of Bosnia in 1580. The Croatian lands in general were reduced to a fraction of what they encompassed, and only the westernmost parts of today's Bosanska Krajina still resisted the Ottoman rule. Nevertheless, the Ottoman armies preferred to advance towards their targets in the northwest through more easily passable terrain, such as along the river Danube, for example Vienna was first besieged in 1529 after the army had gone