A region of Croatia bordering on Bosnia and Herzegovina. Inhabited primarily by ethnic Serbs since the 1500s, the region opposed Croatia's secession from the former Yugoslavia and set up (1990) an autonomous Serbian state. It was retaken by Croatia in 1995, and the Serbian population was largely displaced.
Carniola derives its modern name from the Slavonic word Krajina (frontier).
During this period Bosnia became the generally accepted name for the valley of the Bosna (ancient Basanius); and subsequently for several outlying and tributary principalities, notably those of Soli, afterwards Tuzla; Usora, along the south-eastern bank of the Save; Donji Kraj, the later Krajina, Kraina or Turkish Croatia, in the north-west; and Rama, the modern district of Livno.
From 1322 to 1326 the Croatian nobles successfully withstood the armies of Hungary and Bosnia; from 1337 to 1340, instigated by the Vatican, they carried on a crusade against the Bosnian Bogomils; and in the Krajina (Turkish Croatia) hostilities were resumed at intervals until the Turkish conquest.
The provinces of Agram, Warasdin and Kreutz, previously included in Slavonia, were added to Croatia, to counterbalance the loss of territory in the Krajina.