Along with the Great Andamanese, the Jarawas, the Onge, the Shompen, and the Nicobarese, the Sentinelese are one of the six native and often reclusive peoples of the Andaman and Nicobar Islands.

[3] In 1956, the government of India declared North Sentinel Island a tribal reserve and prohibited travel within 3 nautical miles (5.6 kilometres) of it.

[8] A 1977 report by Heinrich Harrer described a man as 1.60 metres (5 ft 3 in) tall, possibly because of insular dwarfism (the so-called "Island Effect"), nutrition, or simply genetic heritage.

They use spears with bows and arrows to hunt terrestrial wildlife and more rudimentary methods to catch local seafood, such as mud crabs and molluscan shells.

[27] Sentinelese appreciate the value of metal, having scavenged it to create tools and weapons, and accepted aluminum cookware left by the National Geographic Society in 1974.

[13] There is no evidence of them having knowledge of metallurgy outside of cold forging to make tools such as arrow heads,[28] though the Andamanese scholar Vishvajit Pandya notes that Onge narratives often recall voyages by their ancestors to North Sentinel to procure metal.

[16][34] The range of overlap with the Onge language is unknown;[37] the Anthropological Survey of India's 2016 handbook on Vulnerable Tribe Groups considers them mutually unintelligible.

[8] In 1957, the Indian government declared North Sentinel Island a tribal reserve and prohibited travel within 3 nautical miles (5.6 kilometres).

Along with the Great Andamanese, the Jarawas, the Onge, the Shompen, and the Nicobarese, the Sentinelese are one of the six native and often reclusive peoples of the Andaman and Nicobar Islands.

All the passengers and crew reached the beach safely, but as they proceeded for their breakfast on the third day, they were subject to a sudden assault by a group of naked, short-haired, red-painted islanders with arrows that were probably iron-tipped.

After several days of futile search, during which they found abandoned villages and paths, Portman's men captured six people: an elderly man, a woman and four children.

Portman hurriedly sent the children back to North Sentinel Island with a large quantity of gifts in an attempt to establish friendly relations.

[49][clarification needed] In 1896, a convict escaped from the penal colony on Great Andaman Island on a makeshift raft and drifted across to the North Sentinel beach.

When Temple and Portman accompanied him to the tribe and attempted to establish friendly contact, they did not recognize him and responded aggressively by shooting arrows at the group.

[54] In 1967, a group of 20 people, comprising the governor, armed forces and naval personnel, were led by T. N. Pandit, an Indian anthropologist working for the Anthropological Survey of India, to North Sentinel Island to explore it and befriend the Sentinelese.

The crew landed at a safe point on the coast and left gifts in the sand, including a miniature plastic car, some coconuts, a live pig, a doll and aluminium cookware.

[13][58] This expedition also led to the first photograph of the Sentinelese, published by Raghubir Singh in National Geographic magazine, where they were presented as people for whom "arrows speak louder than words".

[59] During the 1970s and 1980s, Pandit undertook several visits to the island, sometimes as an "expert advisor" in tour parties including dignitaries who wished to encounter an aboriginal tribe.

[62] On 2 August 1981, the MV Primrose, carrying a bulk cargo of chicken feed from Bangladesh to Australia, ran aground in rough seas just off North Sentinel Island, stranding a small crew.

[63] After a few days, the captain dispatched a distress call asking for a drop of firearms and reported boats being prepared by more than 50 armed islanders intending to board the ship.

Nearly a week later, the crew was evacuated by a civilian helicopter contracted to the Oil and Natural Gas Corporation (ONGC) with support from Indian naval forces.

[13][63] M. A. Mohammad, a scrap dealer who won a government contract to dismantle the Primrose wreck (about 90 m [300 ft] from the shoreline) and assembled men for the purpose, recorded friendly exchange of fruits and small metal scraps with the Sentinelese, who often canoed to the workplace at low tide:[13][66]After two days, in the early morning when it was low tide we saw three Sentinelese canoes with about a dozen men about fifty feet away from the deck of Primrose.

They took the bananas and came up on board of Primrose and were frantically looking around for smaller pieces of metal scrap [...] They visited us regularly at least twice or thrice in a month while we worked at the site for about 18 months.In 1991, the first instances of peaceful contact were recorded in the course of two routine expeditions by an Indian anthropological team consisting of various representatives of diverse governmental departments,[24][67] including the anthropologist Madhumala Chattopadhyay.

[24] Pandya comments:[70] Those present in the defining moment of physical contact now wished to extract professional mileage from the fact of being actually 'touched' by the Sentinelese during the gift giving exercise.

Every participating member of the contact party wanted to take the credit of being the first to 'touch the Sentinelese', as if it were a great mystical moment of transubstantiation wherein the savage hostile reciprocated a gesture of civilized friendship.

[63][55] In light of the friendly exchanges with the scrap dealers' team and Portman's observations in 1880, Pandya believes that the Sentinelese used to be visited by other tribes.

[8] The Indian government maintained a policy of no deliberate contact, intervening only in cases of natural calamities that might pose an existential threat or to thwart poachers.

[82] Pandya hypothesizes that the aggressive response might have been caused by the sudden withdrawal of those gift-carrying expeditions, which was not influenced or informed by any acts of the Sentinelese.

[92] Eventually, according to Chau's last letter, when he tried to hand over fish and gifts, a boy shot a metal-headed arrow that pierced the Bible he was holding in front of his chest, after which he retreated again.

An anthropologist involved in the case told The Guardian that the risk of a dangerous clash between investigators and the islanders was too great to justify any further attempts.