The Caucasus, also Caucas or Caucasia (for endonyms, see below), is a geopolitical region at the border of Europe and Asia, and situated between the Black and the Caspian sea. It is home to the Caucasus Mountains, which contain Europe’s highest mountain, Mount Elbrus. Politically, the Caucasus region is separated between northern and southern parts.
Located on the peripheries of Turkey, Iran, and Russia, the region has been an arena for political, military, religious, and cultural rivalries and expansionism for centuries. Throughout its history, the Caucasus was usually incorporated into the Iranian world. At the beginning of the 19th century, the Russian Empire conquered the territory from the Qajars.
Ancient kingdoms of the region included Armenia, Albania, Colchis and Iberia, among others. These kingdoms were later incorporated into various Iranian empires, including Media, Achaemenid Empire, Parthia, and Sassanid Empire. In 95-55 BC under the reign of Armenian king of kings Tigranes the Great, the Kingdom of Armenia became an empire, growing to include: Kingdom of Armenia, vassals Iberia, Albania, Parthia and a few Arab tribes, Atropatene, Mesopotamia, Cappadocia, Cilicia, Syria, Assyria, Nabataean kingdom, Judea and Atropatene. The empire stretched from the Caucasian Mountains to Egypt and from the Mediterranean Sea to the Caspian Sea, including a territory of 3,000,000 km2 (1,158,000 sq mi), and becoming the last strong Hellenist king, and the strongest in the region by 67 BC. By this time, Zoroastrianism had become the dominant religion of the region (except for in the Kingdom of Armenia); however, the region would go through two other religious transformations. Owing to the rivalry between Persia and Rome, and later Byzantium, the latter would invade the region several times, although it was never able to hold the region.
However, because the Kingdom of Armenia was the first nation to adopt Christianity as state religion (in 301 AD), and Caucasian Albania and Georgia had become Christian entities, Christianity began to overtake Zoroastrianism. With the Islamic conquest of Persia, the region came under the rule of the Arabs, and soon the Emirate of Armenia was formed. But after several rebellions in 884\885 AD Kingdom of Armenia became independent, and several times crushed Arab armies. At that time, the capital of the Kingdom of Armenia was Ani, with a population of 200,000 and a city of «1001 churches». It was at its peak under the reign of Gagik I, when it stretched from Byzantine Empire to Caucasian Albania, from Caucasian Iberia to Mesopotamia, including also vassal states such as Caucasian Albania and Caucasian Iberia, until in 1045 AD the kingdom was conquered by Byzantine Empire. In the 12th century, the Georgian king David the Builder drove the Muslims out from Caucasus and made the Kingdom of Georgia a strong regional power. In 1194–1204 Georgian Queen Tamar’s armies crushed new Turkish invasions from the south-east and south and launched several successful campaigns into Turkish-controlled Southern Armenia. The Georgian Kingdom continued military campaigns outside of Caucasus. As a result of her military campaigns and the temporary fall of the Byzantine Empire in 1204, Georgia became the strongest Christian state in the whole Near East area. The region would later be conquered by the Ottomans, Mongols, local kingdoms and khanates, as well as, once again, Persia, until its subsequent conquest by Russia.
The region was unified as a single political entity twice – during the Russian Civil War (Transcaucasian Democratic Federative Republic) from 9 April 1918 to 26 May 1918, and under the Soviet rule (Transcaucasian SFSR) from 12 March 1922 to 5 December 1936.
In modern times, the Caucasus became a region of war among the Ottoman Empire, Iran and Russia, and was eventually conquered by the latter (see Caucasian Wars).
In the 1940s, the Chechens and Ingush (480,000 altogether), along with the Balkars, Karachays, Meskhetian Turks (120,000), Kurds and Caucasus Germans (almost 200,000) were deported en masse to Central Asia and Siberia. Eric D. Weitz wrote, «By 1948, according to Nicolas Werth, the mortality rate of the 600,000 people deported from the Caucasus between 1943 and 1944 had reached 25 percent.»
Following the end of the Soviet Union, Georgia, Azerbaijan and Armenia became independent in 1991. The Caucasus region has been subject to various territorial disputes since the collapse of the Soviet Union, leading to the Nagorno-Karabakh War (1988–1994), the Ossetian-Ingush conflict (1989–1991), the War in Abkhazia (1992–1993), the First Chechen War (1994–1996), the Second Chechen War (1999–2009), and the 2008 South Ossetia War.