Banat (UKˈbænɪt,_ˈbɑːn-, USbəˈnɑːt,_bɑːn-; Bánság; Banat) is a geographical and historical region that straddles Central and Eastern Europe and which is currently divided among three countries: the eastern part lies in western Romania (the counties of Timiș, Caraș-Severin, Arad south of the Mureș river, and the western part of Mehedinți); the western part of Banat is in northeastern Serbia (mostly included in Vojvodina, except for a small part included in the Belgrade Region); and a small northern part lies within southeastern Hungary (Csongrád-Csanád County).
The region's historical ethnic diversity was severely affected by the events of World War II. Today, Banat is mostly populated by ethnic Romanians, Serbs and Hungarians, but small populations of other ethnic groups also live in the region. Nearly all are citizens of either Serbia, Romania or Hungary.
During the Middle Ages, the term "banate" designated a frontier province led by a military governor who was called a ban. Such provinces existed mainly in South Slavic, Hungarian and Romanian lands. In South Slavic and other regional languages, terms for "banate" were: Serbian – бановина/banovina, Hungarian – bánság, Romanian – banat and Latin – banatus. Several theories have been proposed for the etymological origin of the regionym "Banat". A first theory claims that it comes from the root of a verb found in several Germanic peoples, namely ban. This term means "to proclaim" or "to announce". From there it passed into medieval Latin, under the form bannum, which means – among the Frankish peoples, for example – "proclamation", but also the district on which the said proclamation was to have effects. Another theory puts forward the Persian origin of the word "ban"; in Persian ban (بان) means "master". From this language, it would have been taken over by the Avars and brought to Pannonia, where they ruled in the 6th–8th centuries. Another interpretation is also related to Avars, according to which the origin of the word "ban" would come from the name of the first khagan of the Avar Khaganate, Bayan I.