a shared history. Colonial era The Andamanese's protective isolation changed with the establishment of a British colonial presence on the islands. Lacking immunity against common infectious diseases of the Eurasian mainland, the large Jarawa habitats on the southeastern regions of South Andaman Island experienced a massive population decline due to disease within four years of the establishment of a colonial presence on the island in 1789. Epidemics of pneumonia, measles and influenza spread rapidly and exacted heavy tolls, as did alcoholism. In the 19th century, a measles epidemic killed 50% of the Andamanese population. By 1875, the Andamanese were already "perilously close to extinction". In 1888, the British government set in place a policy of "organized gift giving" that continued in varying forms until the islands, as part of the British Raj, gained independence from the British Empire. Tensions between the colonial administration and the Andamanese increased due to British officials introducing alcohol and opium to the Andamanese. During mid-19th century, the British government in India established penal colonies on the islands and an increasing number of Indian and Karen arrived, both as settlers and prisoners. In 1867, the British launched the Andaman Islands expedition in order to rescue shipwrecked sailors from the Assam Valley on the Andamanese islands. The expedition was attacked by the Onge people upon their approach to the islands and were forced to withdraw. Four Victoria crosses were awarded to members of the expedition. In 1923, the British ornithologist and anthropologist Frank Finn, who visited the islands in the 1890s while working for the Indian Museum, described the Andamanese as "The World's Most Primitive People", writing: In the 1940s, the Jarawa were attacked by imperial Japanese forces for their hostility. This Japanese attack was criticized as a war crime by many observers. Recent history In 1974, a film crew and anthropologist Triloknath Pandit attempted friendly contact by leaving a tethered pig, some pots and pans, some fruit, and toys on the beach at North Sentinel Island. One of the islanders shot the film director in the thigh with an arrow. The following year, European visitors were repulsed with arrows. On 2 August 1981, the Hong Kong freighter ship Primrose grounded on the North Sentinel Island reef. A few days later, crewmen on the immobile vessel observed that small black men were carrying spears and arrows and building boats on the beach. The captain of the Primrose