Tvrtko I of Bosnia
By the 1370s, the Banate of Bosnia had evolved into the powerful Kingdom of Bosnia following the coronation of Tvrtko I of Bosnia as the first Bosnian king in 1377, further expanding into neighboring Serb and Croat dominions. However, even with the emergence of a kingdom, no concrete Bosnian identity emerged; religious plurality, independent-minded nobility, and a rugged, mountainous terrain precluded cultural and political unity. As Noel Malcolm stated: "All that one can sensibly say about the ethnic identity of the Bosnians is this: they were the Slavs who lived in Bosnia."