Valkó County (
Hungarian: Valkó vármegye,
Croatian: Vukovska županija,
Serbian: Вуковска жупанија) was an administrative unit (
county) of the medieval
Kingdom of Hungary.[1] It was established in the 13th century, and included most territories of the present day
Vukovar-Syrmia County, in modern
Croatia, and western parts of the present day
Syrmia District, in modern
Serbia. The most important cities of the county were
Vukovar and
Ilok. Its territory was conquered by the
Ottoman Turks in the first half of the 16th century.[2]