The Banate of Bosnia, or Bosnian Banate, was a medieval state based in what is today Bosnia and Herzegovina. Although Hungarian kings viewed Bosnia as part of Hungarian Crown Lands, the Banate of Bosnia was a de facto independent state for most of its existence. It was founded in the mid-12th century and existed until 1377 with interruptions under the Šubić family between 1299 and 1324. In 1377, it was elevated to a kingdom. The greater part of its history was marked by a religiopolitical controversy revolving around the native Christian Bosnian Church condemned as heretical by the dominant Chalcedonian Christian churches, namely the Catholic and Eastern Orthodox churches, with the Catholic Church being particularly antagonistic and persecuting its members through the Hungarians.

Bosnia and Herzegovina, sometimes known as Bosnia-Herzegovina and informally as Bosnia, is a country in Southeast Europe, situated on the Balkan Peninsula. It borders Serbia to the east, Montenegro to the southeast, and Croatia to the north and southwest. In the south it has a 20 kilometres long coast on the Adriatic Sea, with the town of Neum being its only access to the sea. Bosnia has a moderate continental climate with hot summers and cold, snowy winters. In the central and eastern regions, the geography is mountainous, in the northwest it is moderately hilly, and in the northeast it is predominantly flat. Herzegovina, the smaller, southern region, has a Mediterranean climate and is mostly mountainous. Sarajevo is the capital and the largest city.