List of sets of four countries that border one another
This is a list of sets of at least four countries that border one another. In the typical case, three countries that border one another form a ring around a landlocked fourth. Examples of states in the centers of such configurations include Burundi, Luxembourg, Malawi and Paraguay.
No more than four contiguous countries can share borders since the complete graph K5 is not planar. On the other hand, non-contiguous countries that have exclaves (sometimes in the form of dependent territories) may form sets of five or more. Also, when regarding point borders as borders (e.g. Utah, Arizona, New Mexico and Colorado at the Four Corners in the U.S.), theoretically any number of regions may meet at one point and all may be considered as bordering one another.
As of the 2006 breakup of the State Union of Serbia and Montenegro, there are at least twelve four-country sets in the world in which each country shares a boundary (land or fresh water) with the others (thirteen when including states with limited recognition).
Contents
Africa
Burundi, Rwanda, Tanzania, Democratic Republic of the Congo
This set has existed since the 1962 change of the united Belgian colony of Ruanda-Urundi into the independent states of Burundi and Rwanda. The Democratic Republic of the Congo had achieved independence in 1960 and was followed the next year by Tanganyika, which would later merge with Zanzibar to form Tanzania. The border between DR Congo and Tanzania is entirely aquatic; the two countries are separated by Lake Tanganyika.
| Borders (km) |  |
 |
 |
 |
|---|---|---|---|---|
| Burundi |
- | 209 | 451 | 233 |
| Rwanda |
209 | - | 217 | 217 |
| Tanzania |
451 | 217 | - | 459 |
| DR Congo |
233 | 217 | 459 | - |
Rwanda, Uganda, Democratic Republic of the Congo, Tanzania
By the time of Ugandan independence in 1962, all of the borders of this set were already established. DR Congo and Tanzania are separated by Lake Tanganyika.
| Borders (km) | |
 |
|
|
|---|---|---|---|---|
| Rwanda |
- | 169 | 217 | 217 |
| Uganda |
169 | - | 765 | 396 |
| DR Congo |
217 | 765 | - | 459 |
| Tanzania |
217 | 396 | 459 | - |
Malawi, Mozambique, Zambia, Tanzania
This set has existed since the 1964 independence of Zambia and Malawi. Mozambique became independent from Portugal in 1975.
| Borders (km) |  |
 |
 |
|
|---|---|---|---|---|
| Malawi |
- | 1569 | 837 | 475 |
| Mozambique |
1569 | - | 419 | 756 |
| Zambia |
837 | 419 | - | 338 |
| Tanzania |
475 | 756 | 338 | - |
Asia
Georgia, Armenia, Azerbaijan, Turkey
This set has existed since the 1991 Dissolution of the Soviet Union. Azerbaijan has a border with Turkey through its exclave of Nakhichevan.
| Borders (km) |  |
 |
 |
 |
|---|---|---|---|---|
| Azerbaijan |
- | 787 | 322 | 9 |
| Armenia |
787 | - | 164 | 268 |
| Georgia |
322 | 164 | - | 252 |
| Turkey |
9 | 268 | 252 | - |
Iran, Armenia, Azerbaijan, Turkey
This set has existed since the 1991 Dissolution of the Soviet Union. Azerbaijan has a border with Turkey through its exclave of Nakhichevan.
| Borders (km) | |
|
|
 |
|---|---|---|---|---|
| Azerbaijan |
- | 787 | 9 | 611 |
| Armenia |
787 | - | 268 | 35 |
| Turkey |
9 | 268 | - | 499 |
| Iran |
611 | 35 | 499 | - |
Nagorno-Karabakh (lim. rec.), Armenia, Azerbaijan, Iran
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This de facto set has existed since the 1992 Nagorno-Karabakh declaration of independence.
The Nagorno-Karabakh Republic is claimed in whole by Azerbaijan and not recognised as independent by any UN member state or observer state.
Europe
Belarus, Latvia, Lithuania, Russia
This set has existed since the 1991 Dissolution of the Soviet Union. The Russian Kaliningrad Oblast, an exclave on the Baltic Sea, creates a Russian border with Lithuania. Belarus and Latvia share boundaries with both mainland Russia and Lithuania.
| Borders (km) |  |
 |
 |
 |
|---|---|---|---|---|
| Belarus |
- | 171 | 502 | 959 |
| Latvia |
171 | - | 576 | 292 |
| Lithuania |
502 | 576 | - | 227 |
| Russia |
959 | 292 | 227 | - |
Belarus, Lithuania, Poland, Russia
This set has existed since the 1991 Dissolution of the Soviet Union.
The Russian Kaliningrad Oblast, an exclave on the Baltic Sea, creates Russian borders with both Lithuania and Poland. Belarus does not border Kaliningrad, but has borders with mainland Russia, Lithuania, and Poland.
| Borders (km) | |
|
 |
|
|---|---|---|---|---|
| Belarus |
- | 502 | 407 | 959 |
| Lithuania |
502 | - | 91 | 227 |
| Poland |
407 | 91 | - | 206 |
| Russia |
959 | 227 | 206 | - |
Belarus, Poland, Russia, Ukraine
This set has existed since the 1991 Dissolution of the Soviet Union.
The Russian Kaliningrad Oblast, an exclave on the Baltic Sea, creates a Russian border with Poland.
| Borders (km) | |
|
|
 |
|---|---|---|---|---|
| Belarus |
- | 407 | 959 | 891 |
| Poland |
407 | - | 227 | 428 |
| Russia |
959 | 227 | - | 1576 |
| Ukraine |
891 | 428 | 1576 | - |
Bosnia and Herzegovina, Croatia, Montenegro, Serbia
This set has existed since the 2006 independence of Montenegro.
Bosnia and Herzegovina has 20 km of coastline on the Adriatic Sea while Croatia borders Montenegro only through the non-contiguous southern portion of the Dubrovačko-neretvanska county, which is an exclave connected to the rest of Croatia only by territorial waters.
| Borders (km) |  |
 |
 |
 |
|---|---|---|---|---|
| Bosnia and Herzegovina |
- | 302 | 225 | 932 |
| Serbia |
302 | - | 203 | 241 |
| Montenegro |
225 | 203 | - | 25 |
| Croatia |
932 | 241 | 25 | - |
Luxembourg, Belgium, France, Germany
This set has existed since the 1839 independence of Luxembourg.
| Borders (km) |  |
 |
 |
 |
|---|---|---|---|---|
| Luxembourg |
- | 73 | 138 | 148 |
| France |
73 | - | 451 | 620 |
| Germany |
138 | 451 | - | 167 |
| Belgium |
148 | 620 | 167 | - |
Netherlands, Belgium, France, Germany
This set has existed since the 1830 Independence of Belgium. Even though the German lands have had many territorial changes, Prussia's Rhine Province and later the various unified German states have always bordered the other three countries.
The only land boundary between the Kingdom of the Netherlands and France is on the Caribbean island of Saint Martin, where the Dutch constituent country of Sint Maarten meets the French Overseas Collectivity of Saint Martin.
| Borders (km) | |
|
 |
|
|---|---|---|---|---|
| Belgium |
- | 167 | 450 | 620 |
| Germany |
167 | - | 577 | 451 |
| Netherlands |
450 | 577 | - | 10 |
| France |
620 | 451 | 10 | - |
South America
Argentina, Bolivia, Brazil, Paraguay
This set has existed since the early-mid 19th century. In the early 19th century all that existed was the Spanish Viceroyalty of the Río de la Plata and the Portuguese colony of Brazil. With the independence of Argentina (revolution in 1810, fully achieved 1816) and Paraguay (1811) the four-border set began to emerge, and was consolidated by the Brazilian and Bolivian independence (1822 and 1825, respectively).
| Borders (km) |  |
 |
 |
 |
|---|---|---|---|---|
| Paraguay |
- | 1290 | 1880 | 750 |
| Brazil |
1290 | - | 1224 | 3400 |
| Argentina |
1880 | 1224 | - | 832 |
| Bolivia |
750 | 3400 | 832 | - |
Near misses
- The 40 km border between China's Xinjiang Autonomous Region and Russia's Altai Republic prevents Mongolia, Kazakhstan, Russia, and the People's Republic of China from forming a set of four countries that border one another.
- The short border between Sikkim in India and Tibet in the People's Republic of China prevents the group Bhutan, India, Nepal and the People's Republic of China from forming such a set.
- The 100 m border between Zambia and Botswana at Africa's four corners is all that prevents Botswana, Namibia, Zimbabwe and Zambia from all touching each other. Depending on definition of a "border", this may or may not be considered a set of four countries that border one another.
- The same 100 m border prevents Botswana from being surrounded by Namibia, Zimbabwe and South Africa, and creating a set.
If one includes states with limited recognition, the following near misses also exist:
- The 10 km wide Gulf of Aqaba between Egypt and Jordan prevents them from forming a set with Israel and the State of Palestine. The Palestinian territories border Egypt through the Gaza Strip and Jordan through the West Bank.
- Western Sahara is disputed between Morocco and the partly recognized Sahrawi Arab Democratic Republic, and each side controls part of the territory, separated by a berm. If one takes the berm to be an international border, then the 8 kilometres (5.0 mi) of SADR-controlled territory between Morocco and Mauritania (roughly halfway between the Moroccan-administered towns of Guelta Zemmur and Smara) are all that prevent Morocco, Mauritania, the SADR and Algeria from forming a set.
-
4 countries CN-KZ-MN-RU.svgRussiaChinaKazakhstanMongolia
-
4 countries BW-NA-ZM-ZW.svgZambiaZimbabweNamibiaBotswana
-
4 countries EG-IL-JO-PS.svg
-
4 countries DZ-MA-MR-EH.svgTerritory held by MoroccoAlgeriaMauritaniaSADR-controlled Western Sahara
Former border sets of at least four countries
The first two sets below include boundaries shared by former colonial empires (specifically territorial claims in South America, Africa, India, Europe, and the East and West Indies), and thus do not reflect continuous areas of land. The third entry refers to Nazi Germany after its annexation of Austria.
| Countries | From | To | Terminal Event |
|---|---|---|---|
 France,[1]  Dutch Republic,[2]  Spain,[3]  Portugal,[4]  Great Britain[5] |
1704 | 1713 | Signing of the Treaty of Utrecht on 11 April 1713 |
Belgium,[6]  Portugal,[7]  German Empire,[8] France,[9]  United Kingdom,[10] Netherlands[11] |
late 19th century | 1914 | Outbreak of World War I |
France,  Germany,  Italy,  Switzerland |
1938 | 1945 | The dissolution of Germany into allied occupation zones[12] |
 Burma,  China,  India,  Pakistan[13] (see below) |
1947 | 1971 | Independence of Bangladesh |
United Arab States,[14]  Iraq,  Jordan,  Saudi Arabia (see below) |
1958 | 1961 | Dissolution of the United Arab States |
-
4 countries CN-IN-MM-PK.svgChinaIndiaBurmaPakistan
-
4 countries IQ-JO-SA-UAS.svgSaudi ArabiaIraqJordanUnited Arab States
See also
- List of land border lengths
- List of political and geographic borders
- List of countries that border only one other country
- List of national border changes since World War I
- List of island nations
- List of divided islands
- Landlocked country
- Enclave
- List of enclaves and exclaves
- Foreign Enclaves in China
- Island country
- Quadripoint
- Tripoint
- Four color theorem
Notes
- ↑ Between 1704 and 1713, France and her colonies neighbored the Netherlands (on Saint Martin), Spain (in Europe), Portugal (between French Guyana and Portuguese Brazil) and Great Britain (between the Indian settlements of Hughli and Chandernagar).
- ↑ Between 1704 and 1713, the Netherlands and her colonies neighbored France (on Saint Martin), Spain (in Europe between Dutch Republic and the Spanish Netherlands), Portugal (between Dutch Suriname and Portuguese Brazil), and Great Britain (between the Indian settlements of Pulicat and Madras.
- ↑ Between 1704 and 1713, Spain and her colonies neighbored France (in Europe), the Netherlands (in Europe between Spanish Netherlands and the Dutch Republic), Portugal (in Europe and South America), and Great Britain (with the 1704 British capture of Gibraltar).
- ↑ Between 1704 and 1713, Portugal and her colonies neighbored France (between Portuguese Brazil and French Guyana), the Netherlands (between Brazil and Dutch Suriname), Spain (in Europe and South America), and Great Britain (between the Indian settlements of Daman and Diu and Surat).
- ↑ Between 1704 and 1713, the Kingdom of Great Britain (and prior to the 1707 Acts of Union, the Kingdom of England) and her colonies neighbored France (between the Indian settlements of Chandernagar and Hughli), the Netherlands (between the Indian settlements of Madras and Pulicat), Spain (with the 1704 British capture of Gibraltar), and Portugal (between the Indian settlements of Daman and Diu and Surat)
- ↑ European Belgium bordered France, the Netherlands, and Germany. The Belgian Congo bordered Portuguese Angola and several French and British colonies in Africa.
- ↑ European Portugal bordered Spain. In 1914, the African colonies of Mozambique, Angola, and Guinea-Bissau bordered territories held by Germany (Namibia and Tanganyika), Great Britain, France, and Belgium. The colony of Timor Leste bordered the Dutch East Indies.
- ↑ Immediately prior to World War I, European Germany bordered the Netherlands, Belgium, and France. African colonies shared boundaries with territories held by Great Britain, Portugal, France, and Belgium
- ↑ European France shared borders with Belgium and Germany. Vast French holdings in colonial Africa abutted colonies possessed by Great Britain, Belgium, Germany, and Portugal. In South America, French Guyana bordered Dutch Suriname.
- ↑ British colonies in Africa shared boundaries with territories held by France, Belgium, Germany, and Portugal. In South America, British Guyana bordered Dutch Suriname.
- ↑ The European Netherlands shared borders with Germany and Belgium. The Dutch East and West India Companies controlled territories that bordered colonies of Portugal (on the island of Timor), Great Britain (Guyana), and France (French Guyana).
- ↑ Date of dissolution assumes that France continued to exist, and include the Occupied Zones, after June 1940; this phrasing ignores the de facto existence of the Italian Social Republic from 1943 on, which was adjacent to the other three states until its last days. The exact date at which a new Austria came into existence may be debatable.
- ↑ From 15 August 1947 to 16 December 1971, Pakistan included modern-day Bangladesh (known as East Pakistan)
- ↑ A short-lived confederation of North Yemen and the United Arab Republic, itself a union of Egypt and Syria.
Sources
- CIA World Factbook CIA World Factbook (public domain)
