The border between the Syrian Arab Republic and the Republic of Turkey (; ) is about long, and runs from the Mediterranean Sea in the west to the tripoint with Iraq in the east. It runs across Upper Mesopotamia for some , crossing the Euphrates and reaching as far as the Tigris. Much of the border follows the Southern Turkish stretch of the Baghdad Railway, roughly along the 37th parallel between the 37th and 42nd eastern meridians. In the west, it almost surrounds the Turkish Hatay Province, partly following the course of the Orontes River and reaching the Mediterranean coast at the foot of Jebel Aqra.
Description
Since Turkey's 1939 appropriation of the Hatay State, the Syrian–Turkish border now touches the Mediterranean coast at Ras al-Bassit, south of Mount Aqra (). Hatay province borders the Syrian Latakia and Idlib governorates. The westernmost (and southernmost) border crossing is at , some 3 km west of Yayladağı. The border reaches its southernmost point at , 2 km west of Bidama, to include the now-abandoned village of Topraktutan (Beysun) in Hatay.
The border now runs north and east, following the Orontes River for a part of its course, where in 2011 construction of a Syria–Turkey Friendship Dam began (but has since been delayed due to the Syrian Civil War), and east to the Bab al-Hawa Border Crossing on the İskenderun–Aleppo road, then further north to the border between Hatay and Gaziantep Province, where it turns sharply east outside of Meidan Ekbis (Afrin District), at .
With the exception of Hatay province, the Turkish side of the border is entirely within the Southeastern Anatolia Region. East of Meidan Ekbis, the border stretches eastward for some 400 km, roughly following the 37th parallel north and passing the 37th to 42nd meridians. From Al-Rai to Nusaybin/Qamishli, the border follows the tracks of the Konya-Baghdad Railway. It crosses the Euphrates River at Jarabulus/Karkamış and passes north of the border town of Kobanî (Ayn al Arab) (built in 1912 as part of the Baghdad Railway construction project). The Raqqa Governorate's Tell Abyad District borders the Turkish Şanlıurfa Province, including the divided border town of Tell Abyad/Akçakale. The Al-Hasakah Governorate, still bordering Şanlıurfa Province, has a border crossing at Ras al-Ayn, connecting to Ceylanpınar. Some 100 km east of Ceylanpınar, the border passes the border town of Nusaybin in the Turkish Mardin Province (ancient Nisibis, the birthplace of Ephraim the Syrian), next to Syrian Qamishli. The Syrian Aleppo Governorate has a long northern boundary with the Turkish Kilis, Gaziantep, and Şanlıurfa provinces.
On the Turkish side, the European route E90 runs alongside the length of the border, crossing the Euphrates at Birecik and the Tigris at Cizre. For the final 30 km the border follows the course of the Tigris, turning towards the south-east, until it reaches the Iraq-Syria-Turkey tripoint at .
History
At the start of the 20th century the entire border region was part of the Ottoman Empire. During the First World War, an Arab Revolt (supported by the British) successfully ousted the Ottomans from Syria and Mesopotamia, however Britain and France had secretly agreed to partition the area between them in 1916 via the Sykes–Picot Agreement.
In 1920 Syria formally became a French mandatory territory, being initially split into a number of states, including the French-controlled Sanjak of Alexandretta (modern Hatay province). By the 1920 Treaty of Sèvres Anatolian Turkey was to be partitioned, with the Syrian-Turkish frontier placed further north than its current position. Turkish nationalists were outraged at the treaty, contributing to the outbreak the Turkish War of Independence; the Turkish success in this conflict rendered Sèvres obsolete. A new border more favourable to Turkey was drawn by the Franco-Turkish Treaty of Ankara in 1921 after negotiations between French Prime Minister Aristide Briand and Turkish Foreign Minister Yusuf Kemal Bey. By the 1923 Treaty of Lausanne Turkey's independence was recognised and a far more generous territorial settlement was agreed upon, albeit at the cost of Turkey formally renouncing any claim to Arab lands. Following Lausanne, the Syrian-Turkish frontier was delimited more precisely between Meidan Ekbis and Nusaybin in 1926, and between Nusaybin and the tripoint with Iraq in 1929. A Final Delimitation Protocol covering the entire boundary east of Hatay was then confirmed and deposited with the League of Nations on 3 May 1930.