Treaty of Neuilly-sur-Seine

The Treaty of Neuilly-sur-Seine was a treaty between the victorious Allies of [World War I] on the one hand, and Bulgaria (1878–1946)|Bulgaria], one of the defeated Central Powers in World War I, on the other. The treaty required Bulgaria to cede various territories.
The treaty was signed on 27 November 1919, in Neuilly-sur-Seine in the Hauts-de-Seine department, just west of Paris in France. The signing ceremony was held in the Hôtel de Ville at Neuilly.
The Treaty of Neuilly was one of the series of treaties after World War I, which included the Treaty of Versailles, the Treaty of Saint-Germain, the Treaty of Trianon, and the Treaty of Sèvres, which were intended to diminish the military and political strength of the defeated members of the Central Powers.
Like those treaties, the Treaty of Neuilly-sur-Seine contained the Covenant of the League of Nations. As a result the United States did not ratify the treaty.

Territorial, economical and military concessions

The treaty required Bulgaria:

to cede Western Thrace to the Entente thereby cutting off Bulgaria's direct outlet to the Aegean Sea.
to sign a convention on population exchange with Greece.
to cede a further area of on its western border with the Kingdom of Serbs, Croats and Slovenes.
to return Dobruja, which according to the Treaty of Bucharest was partially ceded to Bulgaria and partially to the Central Powers, to Romania, thus restoring the border set by the Treaty of Bucharest (1913).
to return property removed from the occupied territory liberated by Bulgarian forces to its rightful owners, or to make compensation.
to reduce its army to 20,000 men.
to pay reparations of £100 million.
to recognize the existence of the Kingdom of Serbs, Croats and Slovenes.

Bulgarian response

In Bulgaria, the results of the treaty are popularly known as the Second National Catastrophe. Bulgaria subsequently regained Southern Dobruja as a result of the Treaty of Craiova. During World War II, together with Nazi Germany, it temporarily reoccupied most of the other territories ceded under the treaty.

Territories ceded to the Kingdom of Serbs, Croats and Slovenes

Four minor regions had been part of Bulgaria from its inception as a principality in 1878, except for the region around Strumitsa, which became part of Bulgaria in 1912. Bulgaria was internationally recognised as an independent country in 1908 and controlled these territories until 1919 when they were ceded to the Kingdom of the Serbs, Croats and Slovenes under the Treaty of Neuilly. The cession of the region was partly a compensation for the occupation of the southern and eastern part of Serbia by Bulgarian troops between 1915 and 1918, and was partly motivated by strategic reasons. The old political boundary between Bulgaria and Serbia followed a chain of high mountain ridges, whereas the new one gave significant military and strategic advantages to the Serbs: it dangerously exposed the Bulgarian capital of Sofia and significantly reduced the military threat to eastern Serbia in case of a Bulgarian invasion.

Area and population

Territories ceded by the treaty to the then Kingdom of Serbs, Croats and Slovenes cover an area of in what is now Serbia and in what is now North Macedonia.
In Serbia, to which the term generally applies in Bulgaria, the territory ceded is split between the modern Serbian District of Pirot and District of Pčinja. It also includes a small section along the Timok River in the municipality and District of Zaječar, composed by eight localities.
In 1919, the area corresponded to the following parts of the Bulgarian okrugs: Kyustendil,, Tzaribrod, Tran, Kula and Vidin. Bulgarian sources claim that the Bulgarian population made 98% of the population in Bosilegrad and 95% of the population in Tzaribrod at the time. In the Yugoslav census of 1931, all South Slavs were simply counted as Yugoslavs so a comparison could not be made. According to the last Census in Serbia from 2002, Bulgarians made 50% and 71% of population in Dimitrovgrad and Bosilegrad respectively.