The

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...

–

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

border ( az, Azərbaycan–İran sərhədi, fa, مرز آذربایجان و ایران) is 765 km (428 m) in length and consists of two non-contiguous sections separated by the Armenia–Iran border.

Description

Western (Nakchivan) section

The border starts in the north-west at the tripoint with Turkey on the

Aras river , az, Araz, fa, ارس, tr, Aras The Aras (also known as the Araks, Arax, Araxes, or Araz) is a river in the Caucasus. It rises in eastern Turkey and flows along the borders between Turkey and Armenia, between Turkey and the Nakhchivan excl ...

, continuing along this river south-eastwards, through the Aras reservoir (created by the

Aras Dam The Aras Dam ( az, Araz su anbarı; fa, سد ارس) is an embankment dam on the Aras River along the border of Iran and Azerbaijan. It is located downstream of Poldasht in West Azerbaijan Province, Iran and Nakhchivan City in Nakhchivan Autono ...

) and down to the western Armenian tripoint.

Eastern section

The border starts in the west at the eastern Armenian tripoint on the Aras river, and then follows this river as it flows north-eastwards. The border leaves the river at a point south of

Bəhramtəpə Bəhramtəpə (also, Bəhrəmtəpə, Agakhanly, Pervomayskoye, and Pervoye Maya; russian: Бирмай; formerly Bir May) is a village and municipality in the Imishli Rayon of Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Rep ...

, turning sharply south-eastwards and proceeding across the

Mugan plain Mughan plain ( az, Muğan düzü, مغان دوزو; ) is a plain stretching from northwestern Iran to the southern part of the Republic of Azerbaijan. The highest density of irrigation canals is in the section of the Mughan plain which lies in ...

to the Bolgarchay river. The border then follows this river south forming a broad S-shape. The river ends near Yardımlı, with the border then curving south-eastwards, proceeding overland in that direction through the

Talysh Mountains Talysh Mountains ( tly, Tolışə Bandon, script=Latn, fa, کوه‌های تالش, Kuhhâye Tâleš; az, Talış dağları) is a mountain range in far southeastern Azerbaijan and far northwestern Iran within Ardabil Province and Gilan Provin ...

, then turning east along the Astarachay river, following its course out to the

Caspian Sea The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...

History

During the 19th century the Caucasus region was contested between the declining

Ottoman Empire The Ottoman Empire, * ; is an archaic version. The definite article forms and were synonymous * and el, Оθωμανική Αυτοκρατορία, Othōmanikē Avtokratoria, label=none * info page on book at Martin Luther University) ...

Persia Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

and

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

, which was expanding southwards. By the

Russo-Persian War (1804–1813) The 1804–1813 Russo-Persian War was one of the many wars between the Persian Empire and Imperial Russia, and began like many of their wars as a territorial dispute. The new Persian king, Fath Ali Shah Qajar, wanted to consolidate the north ...

and the subsequent

Treaty of Gulistan The Treaty of Gulistan (russian: Гюлистанский договор; fa, عهدنامه گلستان) was a peace treaty concluded between the Russian Empire and Iran on 24 October 1813 in the village of Gulistan (now in the Goranboy Distri ...

, Russia acquired the bulk of what is now Azerbaijan and parts of Armenia; a border was drawn which is the modern border between Iran and Azerbaijan (excluding the Nakhichevan section) and Iran and Armenia. Following the

Russo-Persian War (1826–1828) The Russo-Persian War of 1826–1828 was the last major military conflict between the Russian Empire and Persia. After the Treaty of Gulistan that concluded the previous Russo-Persian War in 1813, peace reigned in the Caucasus for thirteen y ...

and the

Treaty of Turkmenchay The Treaty of Turkmenchay ( fa, عهدنامه ترکمنچای; russian: Туркманчайский договор) was an agreement between Qajar Iran and the Russian Empire, which concluded the Russo-Persian War (1826–28). It was second o ...

Persia was forced to cede Nakhchivan and the rest of Armenia to Russia; the Aras was extended as the border up to the Ottoman tripoint, thus finalising what would become the Azerbaijan–Iran border. During the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

Russian Communists staged a successful

revolution In political science, a revolution (Latin: ''revolutio'', "a turn around") is a fundamental and relatively sudden change in political power and political organization which occurs when the population revolts against the government, typically due ...

in 1917, whilst the peoples of the southern Caucasus had declared the

Transcaucasian Democratic Federative Republic The Transcaucasian Democratic Federative Republic (TDFR; (), (). 22 April – 28 May 1918) was a short-lived state in the Caucasus that included most of the territory of the present-day Armenia, Azerbaijan and Georgia, as well as pa ...

in 1918. Internal disagreements led to

Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...

leaving the federation in May 1918, followed shortly thereafter by

Armenia Armenia (), , group=pron officially the Republic of Armenia,, is a landlocked country in the Armenian Highlands of Western Asia.The UNbr>classification of world regions places Armenia in Western Asia; the CIA World Factbook , , and ''Ox ...

and

. By its very name the newly independent Azerbaijan caused tensions with Persia, as it seemed to imply a claim to Iran's

Azerbaijan region Azerbaijan or Azarbaijan ( fa, آذربایجان, ''Āzarbāijān'' ; az-Arab, آذربایجان, ''Āzerbāyjān'' ), also known as Iranian Azerbaijan, is a historical region in northwestern Iran that borders Iraq, Turkey, the Nakhchiva ...

. In 1920 Russia's

Red Army The Workers' and Peasants' Red Army (Russian: Рабо́че-крестья́нская Кра́сная армия),) often shortened to the Red Army, was the army and air force of the Russian Soviet Federative Socialist Republic and, after ...

invaded Azerbaijan and Armenia, ending the independence of both, followed shortly thereafter by Georgia. All three states were incorporated into the

Transcaucasian SFSR , conventional_long_name = Transcaucasian Socialist Federative Soviet Republic , common_name = Transcaucasian SFSR , p1 = Armenian Soviet Socialist RepublicArmenian SSR , flag_p1 = Flag of SSRA ...

within the

USSR The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nationa ...

, before being separated in 1936. A Soviet-backed separatist state in Iranian Azerbaijan was established 1945 but was soon quashed by Iranian forces. An Iran-USSR border convention in 1954 made some minor adjustments along the frontier in the Mugan plain and near Deman and Namin, to Iran's benefit. On-the-ground demarcation then followed, with a final agreement being agreed upon in 1957. In 1970 some further adjustments were made to the Nakhchivan section of the border following the creation of the Aras dam. Following the collapse of the USSR in 1991 Azerbaijan gained independence and inherited its section of the Iran-USSR border. Iran quickly recognised the new state, though relations cooled over Iranian fears of Azerbaijan's potential claims to its territory as part of a ' Greater Azerbaijan', with Iran championing Armenia in the

First Nagorno-Karabakh War The First Nagorno-Karabakh War, referred to in Armenia as the Artsakh Liberation War ( hy, Արցախյան ազատամարտ, Artsakhyan azatamart) was an ethnic and territorial conflict that took place from February 1988 to May 1994, in th ...

.James P. Nichol. ''Diplomacy in the Former Soviet Republics'', Praeger/Greenwood, 1995, , p. 150 Following the war Armenia was left in control of the westernmost section of the 'mainland' Azerbaijan–Iran border. Relations between Iran and Azerbaijan have improved somewhat since the accession of

Hassan Rouhani Hassan Rouhani ( fa, حسن روحانی, Standard Persian pronunciation: ; born Hassan Fereydoun ( fa, حسن فریدون, links=no); 12 November 1948) is an Iranian politician who served as the seventh president of Iran from 2013 to 2021. ...

in Iran. During the

2020 Nagorno-Karabakh War The Second Nagorno-Karabakh War was an armed conflict in 2020 that took place in the disputed region of Nagorno-Karabakh and Armenian-occupied territories surrounding Nagorno-Karabakh, the surrounding territories. It was a major escalation of ...

, Azerbaijan gained complete control of the western section of the border with Iran within one month from the self-proclaimed

Republic of Artsakh Artsakh, officially the Republic of Artsakh () or the Nagorno-Karabakh Republic (),, is a list of states with limited recognition, breakaway state in the South Caucasus whose territory is internationally recognised as part of Azerbaijan ...

, ultimately restoring Azerbaijani control over the border.

Border crossings

There are crossings between 'mainland' Azerbaijan and Iran at Bilasuvar and Astara. Crossings between Iran and Nakchivan are at Jolfa/Julfa and

Poldasht Poldasht ( fa, پلدشت; Azerbaijani: Daş Körpü , also Romanized as Pol Dasht, Pol’desht, Pol-e Dasht, and Pul Dasht; also known as Araplar) is a city and capital of Poldasht County, West Azerbaijan Province, Iran. At the 2016 census, its ...

–Shahtakhti.

References