A clear history of the Andaman & Nicobar Islands can be had only from a British Survey of these islands conducted in 1777. The Andaman & Nicobar Islands remained the abode of the Negritos and the Mongoloids respectively, who occupied the Islands for centuries. These islands remained secluded from the mainland till the end of the 18th Century when people from the outside world first arrived. The history of these islands could be divided into four broad periods the period of seclusion and piratical disturbances a) the British regime - a period of foreign intrusion and settlement b) the Japanese regime c) and the Post-Independence period. In the Second Century, the Andaman and Nicobar Islands were located in the maps prepared by the great Greek astronomer, mathematician and geographer, Claudius Ptolemaeus, which possibly is the earliest reference to these islands. The early history of Nicobar is not well known although these islands were familiar to traders in ancient times, the islands being situated close to the trade route to the Far East. Though little is known about Portuguese activities in these islands, it is evident that the Portuguese missionaries started preaching Christianity among the islanders. The Nicobarese language also reflects a few Portuguese words.