The Banat belonged to Hungary until the beginning of twentieth century. It was a rich agricultural region which also possessed significant mining, metal-working and animal husbandry potential in its eastern, mountainous half. The region was bordered on three sides by the lower Mureș, Tisza, and the Danube. As concerns ethnicity, it was characterized by an unparalleled complexity, being nicknamed “Europe’s harlequin coat.” Soon after the outbreak of World War One, the region became the object of competing disputations among the neighbouring states of Romania, Serbia and later Yugoslavia. Allocating the province formerly known as the Banat of Timișoara to a new state proved one of the most difficult problems submitted to the Peace Conference in Paris. Although this subject was discussed in the historical literature before, it is still open to new contributions both from the point of view of primary sources as well as from that of interpretations. The earliest texts dealing with this topic were propaganda works commissioned by those governments interested in sustaining territorial claims before the victorious Entente’s decision-makers. The authors of both sides approaching this topic at a later stage have gradually mitigated their one-sidedness more or less successfully. The most important primary sources consist of documents produced by the French Ministry of Foreign Affairs during World War One and the Peace Conference in Paris. The debates taking place in the Commission for Romanian and Yugoslav affairs, aiming to decide between the Romanian position of “all or nothing” and the Serbian one with regards to the division of the Banat, were in reality formal. The decision to adopt the latter position had been already made by the Supreme Council of the conference. With small corrections introduced in 1923, the decision regarding the state borders between Romania and Yugoslavia, proposed in 1919, although regarded as not viable at the time, has remained in force to the present.