The territory is north of Aceh in Indonesia and separated from Thailand and Burma by the Andaman Sea. It comprises two island groups, the Andaman Islands and the Nicobar Islands, separated by the 10°N parallel, with the Andamans to the north of this latitude, and the Nicobars to the south. The Andaman Sea lies to the east and the Bay of Bengal to the west.
The earliest archaeological evidence yet documented goes back some 2,200 years; however, genetic and cultural studies suggest that the indigenous Andamanese people may have been isolated from other populations since the Middle Paleolithic. In that time, the Andamanese have diversified into distinct linguistic, cultural and territorial groups.
The Nicobar Islands appear to have been populated by people of various backgrounds. At the time of the European contact, the indigenous inhabitants were the Nicobarese people, speaking a Mon-Khmer language; and the Shompen, whose language is of uncertain affiliation. Both are unrelated to the Andamanese.
Rajendra Chola I (1014 to 1042 CE), one of the Tamil Chola dynasty kings, conquered the Andaman and Nicobar Islands to use them as a strategic naval base to launch a naval expedition against the Sriwijaya Empire (a Hindu-Malay empire based on the island of Sumatra, Indonesia). They called the islands 'Tinmaittivu' ("impure islands" in Tamil).
The islands provided a temporary maritime base for ships of the Maratha Empire in the 17th century. The legendary admiral Kanhoji Angre established naval supremacy with a base in the islands and is credited with attaching those islands to India.
The history of organised European colonisation on the islands began when the Danish settlers of the Danish East India Company arrived in the Nicobar Islands on 12 December 1755. On 1 January 1756, the Nicobar Islands were made a Danish colony, first named New Denmark, and later (December 1756) Frederick's Islands (Frederiksøerne). During 1754–1756 they were administrated from Tranquebar (in continental Danish India). The islands were repeatedly abandoned due to outbreaks of malaria between 14 April 1759 and 19 August 1768, from 1787 to 1807/05, 1814 to 1831, 1830 to 1834 and gradually from 1848 for good.
In 1789 the British set up a naval base and penal colony on Chatham Island next to Great Andaman, where now lies the town of Port Blair. Two years later the colony was moved to Port Cornwallis on Great Andaman, but it was abandoned in 1796 due to disease.
In 1858 the British again established a colony at Port Blair, which proved to be more permanent. The primary purpose was to set up a penal colony for dissenters and independence fighters from the Indian subcontinent. The colony came to include the infamous Cellular Jail.
In 1872 the Andaman and Nicobar islands were united under a single chief commissioner at Port Blair.
World War II
During World War II, the islands were practically under Japanese control, only nominally under the authority of the Arzi Hukumate Azad Hind of Netaji Subhas Chandra Bose. Bose visited the islands during the war, and renamed them as "Shaheed-dweep" (Martyr Island) and "Swaraj-dweep" (Self-rule Island).
General Loganathan, of the Indian National Army was made the Governor of the Andaman and Nicobar Islands. On 22 February 1944 he along with four INA officers — Major Mansoor Ali Alvi, Sub. Lt. Md. Iqbal, Lt. Suba Singh and stenographer Srinivasan—arrived at Lambaline Airport in Port Blair. On 21 March 1944 the Headquarters of the Civil Administration was established near the Gurudwara at Aberdeen Bazaar. On 2 October 1944, Col. Loganathan handed over the charge to Maj. Alvi and left Port Blair, never to return. The islands were reoccupied by British and Indian troops of the 116th Indian Infantry Brigade on 7 October 1945, to whom the remaining Japanese garrison surrendered.
At the independence of both India (1947) and Burma (1948), the departing British announced their intention to resettle all Anglo-Indians and Anglo-Burmese on the islands to form their own nation, although this never materialised. It became part of the Indian union in 1950 and was declared a union territory in 1956.
The 2004 tsunami
On 26 December 2004 the coasts of the Andaman and Nicobar Islands were devastated by a high tsunami following the 2004 Indian Ocean earthquake. More than 2,000 people were confirmed dead, more than 4,000 children were orphaned or suffered the loss of one parent, and a minimum of 40,000 people were rendered homeless. The worst affected Nicobar islands were Katchal and Indira Point; the latter subsided 4.25 metres and was partially submerged in the ocean. The lighthouse at Indira Point was damaged but has been repaired since then. The territory lost a large amount of area which is now submerged. The territory which was at is now merely at .
While newer settlers of the islands suffered the greatest casualties from the tsunami, most of the aboriginal people survived because oral traditions passed down from generations ago warned them to evacuate from large waves that follow large earthquakes.