TheTreaty of Constantinople (Treaty of İstanbul) was a treaty between theOttoman Empire and theKingdom of Bulgaria signed on 29 September 1913 after theSecond Balkan War at the Ottoman capitalConstantinople,[1] modern İstanbul.
 | |
| Type | Peace treaty |
|---|---|
| Signed | 29 September 1913 (1913-09-29) |
| Location | Constantinople |
| Parties | |
| Languages | Bulgarian,Ottoman Turkish |
In theFirst Balkan War, the coalition ofBulgaria,Serbia,Greece andMontenegro defeated the Ottoman Empire. The Turks lost nearly all theirEuropean possessions, save for a small territory around theSea of Marmara by theTreaty of London.[2] The Ottomans however were able to recoverEastern Thrace during theSecond Balkan War.[3] Although peace talks between Bulgaria and her other neighbours were held inBucharest, the Ottoman Empire was not represented there and conducted separate negotiations which led to the Treaty of Constantinople.
The terms of the treaty were:[4][5]
The treaty largely defines the modern-day borders betweenEastern Thrace (European Turkey), Bulgaria and Greece.
The Ottoman Empire and Bulgaria were allies in theCentral Powers in theFirst World War. Before the Bulgarian entry into the war, the Ottoman government decided to cedeDidymoteicho to Bulgaria (to persuade it to join the war on the Central Powers side) by way of theBulgarian–Ottoman convention (1915). However, the Central Powers were defeated in 1918 and Bulgaria lost bothWestern Thrace andDidymoteicho toGreece.
Under the terms of the abortiveTreaty of Sèvres, Turkey was to cede almost all of Eastern Thrace to Greece, but the proposed territorial changes were negated byTurkey's victory overGreece during theGreco-Turkish War of theTurkish War of Independence and the subsequentTreaty of Lausanne, which reaffirmed the borders established by the Treaty of Constantinople and the Bulgarian-Ottoman convention.
