The boundary between
Asia and
Europe is unusual among continental boundaries because of its largely mountain-and-river-based characteristics north and east of the Black Sea. Asia and Europe are considered separate continents for historical reasons; the division between the two goes back to the
early Greek geographers. In the modern sense of the term "continent",
Eurasia is more readily identifiable as a "continent", and Europe has occasionally been described as a
subcontinent of Eurasia.
Mainland History region as part of the European continent. map of Europe from 1874, with an alternative southern limit at the Turkish border. The threefold division of the
Old World into Africa, Asia, and Europe has been in use since the 6th century BC by
early Greek geographers such as
Anaximander and
Hecataeus. This convention was subsequently revised and the boundary between Asia and Europe was considered to be the
Tanais (the modern Don River). This is the convention used by the Roman era authors
Posidonius,
Strabo and
Ptolemy. Throughout the Middle Ages and into the 18th century, the traditional division of the landmass of
Eurasia into two continents, Asia and Europe, followed Ptolemy, with the boundary following the
Turkish Straits, the
Black Sea, the
Kerch Strait, the
Sea of Azov, and the
Don (known in antiquity as the Tanais). But maps produced during the 16th to 18th centuries tended to differ in how to continue the boundary beyond the Don bend at
Kalach-na-Donu (where it is closest to the Volga, now joined with it by the
Volga–Don Canal), into territory not described in any detail by the ancient geographers.
Philip Johan von Strahlenberg in 1725 was the first to depart from the classical Don boundary by drawing the line along the
Volga, following the Volga north until the
Samara Bend, along
Obshchy Syrt (the
drainage divide between the
Ural and
Volga rivers) and then north along the
Ural Mountains. The mapmakers continued to differ on the boundary between the lower Don and Samara well into the 19th century. The
1745 atlas published by the
Russian Academy of Sciences has the boundary follow the Don beyond Kalach as far as
Serafimovich before cutting north toward
Arkhangelsk, while other 18th- to 19th-century mapmakers such as
John Cary followed Strahlenberg's prescription. To the south, the
Kuma–Manych Depression was identified circa 1773 by a German naturalist,
Peter Simon Pallas, as a valley that, once upon a time, connected the Black Sea and the Caspian Sea, and subsequently was proposed as a natural boundary between continents. By the mid-19th century, there were three main conventions, one following the Don, the
Volga–Don Canal and the Volga, the other following the Kuma–Manych Depression to the Caspian and then the Ural River, and the third abandoning the Don altogether, following the
Greater Caucasus watershed to the Caspian. The question was still treated as a controversy in geographical literature of the 1860s, with
Douglas Freshfield advocating the Caucasus crest boundary as the best possible, citing support from various modern geographers. In Russia and the
Soviet Union, the boundary along the Kuma–Manych Depression was the most commonly used as early as 1906. Despite this, outside the geographical context, the territories of the North and South Caucasus were often classified as the European part of the country, for political, economic, and historical-cultural reasons. Thus, the political boundaries of Europe in the southern section were based on political and administrative borders. According to this principle, the extended boundary between Europe and Asia followed the state border of the USSR with Turkey and Iran (now it is the border from Georgia, Armenia and Azerbaijan). In 1958, the Soviet Geographical Society formally recommended that the boundary between Asia and Europe be drawn in textbooks from
Baydaratskaya Bay, on the
Kara Sea, along the eastern foot of the Ural Mountains, then following the
Ural River until the
Mugodzhar Hills, and then the
Emba River; and Kuma–Manych Depression, thus placing the Caucasus entirely in Asia and the Urals entirely in Europe. However, most geographers in the Soviet Union favoured the boundary along the Caucasus crest and this became the standard convention in the latter 20th century, although the Kuma–Manych boundary remained in use in some 20th-century maps.
Modern definition in
Orenburg in
Russia. The bridge is between
Asia and
Europe , Ural Mountains, Russia. It reads "Europe", above a crossed-out "Asia", as one enters Europe and leaves Asia The modern border between Asia and Europe is a historical and cultural construct and, for that reason, its definition has varied. One commonly accepted border follows the
Aegean Sea, the
Dardanelles–
Sea of Marmara–
Bosporus (together known as the
Turkish Straits), the
Black Sea, along the
watershed of the
Greater Caucasus, the northwestern portion of the
Caspian Sea, and along the
Ural River and
Ural Mountains to the
Kara Sea, as mapped and listed in most atlases including that of the
National Geographic Society and as described in
The World Factbook. According to this particular definition,
Georgia is a transcontinental country with some of its northern portions (such as
Kazbegi Municipality,
Khevsureti, and
Tusheti) geographically located in
Eastern Europe, north of the
Greater Caucasus Watershed, whereas the country's south is arguably in Asia. Similarly, according to this one particular definition,
Azerbaijan is a transcontinental country with some northern portions (e.g.
Khachmaz,
Quba,
Qusar,
Shabran, and
Siazan) located north of the
Greater Caucasus Watershed and thus geographically in Europe, whereas the rest arguably falls under Asia. Georgia actively identified as European throughout the 19th and 20th centuries. In the 21st century, Georgia is regarded as a European country for historical, cultural, religious, and political reasons. The international geographic community has never reached a universal agreement on continental borders, especially with regard to the Caucasus region between the Black and Caspian seas. As
Encyclopædia Britannica explains: "The watershed of the Greater Caucasus, the backbone of the system, traditionally has been part of the line dividing Europe and Asia, but Europe's eastern boundary has been the subject of much debate. One widely accepted scheme draws the dividing line along the crest of the Greater Caucasus range, putting the portion of the region north of the line in Europe and the portion south of it in Asia. Another puts the western portion of the Caucasus region in Europe and the eastern part (the bulk of Azerbaijan and small portions of Armenia, Georgia, and Russia's Caspian Sea coast) in Asia. Still another scheme identifies the
Aras River and the Turkish border as the line of continental demarcation, thereby locating Armenia, Azerbaijan, and Georgia in Europe."
Russia and
Turkey are transcontinental states with territory in both Asia and Europe by any definition. Russia is historically, culturally, and politically a European state, with a history of
imperial conquests in Asia. The situation for Turkey is inverse, as that of an Asian country with
imperial conquests in Europe.
Kazakhstan is also a transcontinental state by this definition, with its
West Kazakhstan and
Atyrau provinces extending on either side of the Ural River, although it is considered a
central Asian country that extends to Europe. The Turkish city
Istanbul is a transcontinental city because it lies on both sides of the Bosporus (one of the Turkish Straits). The Russian and Kazakhstani cities of
Magnitogorsk,
Orenburg, and
Atyrau fall on the Ural River, making them transcontinental cities as well. This Ural River delineation is the only segment not to follow a major mountain range or wide water body, both of which often truly separate populations. However, the Ural River is the most common division used by authorities, is the most prominent natural feature in the region, and is the "most satisfactory of those (options) proposed" which include the
Emba River, a much smaller stream cutting further into
Central Asian Kazakhstan. The Ural River bridges in
Atyrau and
Orenburg are even labeled with permanent monuments carved with the word "Europe" on one side, "Asia" on the other. Because the
Kazakhs are an Asian people, after the collapse of the
USSR, the option according to which the border of Europe runs from the Caspian Sea along the state border between
Russia and
Kazakhstan to the
Ural River has also gained popularity. The
Kuma–Manych Depression (more precisely, the
Manych River, the
Kuma–Manych Canal, and the
Kuma River) remains cited less commonly as one possible natural boundary in contemporary sources. This definition peaked in prominence in the 19th century; however, it has declined in usage over time. This is because it included in Asia certain areas of Russia in
Ciscaucasia (such as
Stavropol,
Krasnodar, and areas just south of
Rostov-on-Don) seen as too European to be Asian. One formal means by which states are grouped into one specified continental area or another is by using the definition used for statistical purposes by the
United Nations Statistics Division (UNSD): According to UNSD, "assignment of countries or areas to specific groupings is for statistical convenience and does not imply any assumption regarding political or other affiliation of countries or territories". Furthermore, the UNSD classification often differs from those of other
United Nations organizations. For instance, while UNSD includes Georgia and Cyprus in Western Asia, the
United Nations Industrial Development Organization and
UNESCO include both states in Europe. The
Council of Europe and the
European Political Community includes transcontinental or Eurasian states, such as
Armenia, Azerbaijan,
Cyprus, Georgia, and
Turkey as members.
Cyprus is a member of the
European Union, whereas the
European Parliament noted that Georgia is eligible to apply for EU membership "like any other European state". On 14 December 2023, Georgia was officially granted EU Candidate status. The
Treaty on Conventional Armed Forces in Europe defined the eastern boundary of Europe to be the Ural Mountains, Ural River, and Caspian Sea. However, it also included all of the territory of the then-Soviet republics of Armenia, Azerbaijan, and Georgia, as well as areas of Turkey north of the
39th parallel (among other areas of Turkey).
Islands Cyprus is an island of the Mediterranean located on the Asian continental shelf, geologically a part of the
Anatolian Plate and adjacent to
Anatolia, by which it is sometimes associated with Asia (
Western Asia), as in the
United Nations geoscheme. Despite differences regarding its geographic affiliation, the
Republic of Cyprus was nevertheless admitted to the Council of Europe in 1961 and joined the EU in 2004. The northern part of the island functions as the unrecognized (except by Turkey)
Turkish Republic of Northern Cyprus. The Greek
North Aegean islands and the
Dodecanese lie on the coast of the Asian part of Turkey (on the Asian continental shelf). Thus, generally, these island groups could be considered part of Asia. More specifically, the small islands of
Kastellorizo,
Strongyli Megistis, and
Ro (all these islands are still in the Dodecanese group) are directly to the south of the Turkish
Anatolia coastline, of which they are directly adjacent. Additionally, they lie at some distance to the east of the rest of the Dodecanese group in the direction of
Cyprus and the Turkish city of
Antalya. Akin to Cyprus, these small islets would nominally be considered Asian if only the continental shelf were used to define the boundary, but for history and cultural influences they are considered a part of Europe. Russia's
Vaygach Island and
Novaya Zemlya extend northward from the northern end of the
Ural Mountains and are a continuation of that chain into the
Arctic Ocean. While Novaya Zemlya was variously grouped with Europe or with Asia in 19th-century maps it is now usually grouped with Europe, the continental boundary considered to join the Arctic Ocean along the southern shore of the
Kara Sea. The Russian Arctic
archipelago of
Franz Josef Land farther north is also associated with Europe. ==Asia and North America==