During World War II, when Czechoslovakia was split temporarily, some of the Czechoslovak part of Zemplen county was occupied by Hungary under the First Vienna Award, and added to the counties Zemplén and Ung. After World War II, the pre-war border was restored, and the Hungarian county Zemplén merged with the county Borsod and the Hungarian part of Abov-Turňa to form the present Borsod-Abaúj-Zemplén county. Since the separation of Czechoslovakia into Slovakia and the Czech Republic in 1993, the northern part of Zemplín is part of Slovakia, divided between eastern parts of Košice Region and Prešov Region.