A Chronology of the Bonin Islands

Drop beneath the surface off Chichijima and you are floating above one of the most isolated archipelagos on Earth—a chain that has never been linked to any continent. That same isolation that shaped the islands' famous endemic life also shaped a human story unlike anywhere else in Japan: a remote outpost first settled by Americans, Europeans, and Pacific Islanders, later annexed by Tokyo, fought over in the Pacific War, governed for two decades by the U.S. Navy, and finally protected as a UNESCO World Natural Heritage site. Knowing that story makes a dive trip to the Ogasawara Islands richer. Here is how it unfolded.

An empty name: discovery and the meaning of "Bonin"

The islands lie roughly 1,000 kilometres south of Tokyo, scattered across open Pacific water. For most of recorded history they sat empty. Spanish and other passing vessels noted them in the sixteenth century, and a Japanese merchant ship blown off course is recorded landing on Hahajima in 1670. Japanese tradition also credits a samurai named Ogasawara Sadayori with an earlier claim, which is why the islands carry the formal name Ogasawara today.

The English name tells the older truth about the place. "Bonin" is a corruption of the Japanese bunin or munin (無人), meaning "no people"—the uninhabited islands. When the first permanent settlers arrived, they were not displacing anyone; they were starting from nothing on bare volcanic land.

1830: a colony of many flags

The modern human history begins in 1830. With backing arranged through the British consul in Hawaii, a small party sailed from Honolulu to settle Chichijima—then known to Westerners as Peel Island. The founders were a striking mix for their time: Nathaniel Savory of Massachusetts, an Englishman from Devon, a Genoese-born sailor, a Dane, and a group of Hawaiian men and women who did much of the hard work of building a community from scratch.

They cleared ground, raised vegetables, grains and livestock, fished, and sold fresh provisions to the whaling ships that increasingly used the harbour as a mid-Pacific resupply stop. Savory emerged as the colony's leading figure, and the settlement became a genuinely multinational, multilingual place. In 1853 the American naval officer Commodore Matthew Perry—on his way to force open Japan—stopped at the islands, bought land at the anchorage from Savory, and floated the idea of an American coaling station there.

1876: annexation by Japan

Perry's interest never became American sovereignty. Instead, the newly modernising Meiji government moved to formalise its own claim. In 1876 the Ogasawara Islands were internationally recognised as Japanese territory, with the consent of the Western powers. The existing foreign-born settlers were not expelled; by 1882 they had been naturalised as Japanese subjects. Their descendants—known locally as the Ōbeikei, the "Westerners"—kept their family names, their churches, and elements of their language even as the islands grew steadily more Japanese, with new settlers arriving to farm, fish, and harvest sugar.

War: evacuation, Iwo Jima, and the Chichijima incident

By the eve of the Pacific War, more than 7,000 people lived across the inhabited islands. In 1944, as American forces advanced and the islands' airfields and radio stations became military targets, the great majority of civilians—around 6,900 of them—were evacuated to the Japanese mainland. Ogasawara was left a garrisoned fortress.

The wider region became one of the war's most savage theatres. The volcanic island of Iwo Jima (Iwo To), part of the same administrative chain to the south, saw the ferocious 1945 battle whose flag-raising became an enduring image of the conflict. On Chichijima itself, American carrier aircraft repeatedly struck the island in 1944. One downed airman, a 20-year-old naval pilot and future U.S. president, George H. W. Bush, was rescued from the water by a submarine. Several of his fellow captured airmen were not so fortunate: their murder by Japanese officers became known as the Chichijima incident and was prosecuted at a postwar war-crimes trial.

1945–1968: under American administration

When the war ended, the islands did not simply return to normal. They passed under United States military administration, formalised by the San Francisco Peace Treaty in 1952. In an unusual decision, only the Ōbeikei families of Western descent were initially permitted to come home; the much larger Japanese civilian population remained in exile on the mainland, unable to return to homes and graves a thousand kilometres away. For more than two decades Chichijima was effectively a small American naval community in the middle of the Pacific.

1968: reversion to Japan

That long limbo ended on 26 June 1968, when the United States returned administrative control of the Ogasawara Islands to Japan and the navy withdrew. After a quarter-century away, the evacuated islanders were at last allowed to return. The blended community—Japanese families, Ōbeikei descendants of Savory and his companions, and a steady trickle of new settlers—began rebuilding island life, this time oriented toward fishing, agriculture, and a growing interest in the islands' extraordinary nature.

2011: a World Natural Heritage site

Because the Bonins rose from the sea in isolation and were never joined to a continent, their plants and animals evolved largely on their own. The result is a living showcase of evolution—high rates of endemism among land snails, plants, and creatures such as the Bonin flying fox—which is why the chain is sometimes called the "Galápagos of the Orient." In June 2011, UNESCO inscribed the Ogasawara Islands as a World Natural Heritage site, recognising those ongoing evolutionary processes and committing Japan to protecting the islands' fragile ecosystems on land and in the surrounding sea.

From bunin—"no people"—to a globally protected sanctuary: few small islands have travelled so far in under two centuries.

For the diver

That heritage protection is also why the waters here feel so untouched. The same remoteness that kept the islands empty, drew a multinational settlement, and earned UNESCO recognition is what gives Ogasawara its clear blue water, healthy reefs, and reliable encounters with dolphins and seasonal whales. The only way in is the long ferry from Tokyo, which makes every dive feel earned. For seasons, marine life, conditions, and how to reach the islands, see our Ogasawara diving guide, and find the archipelago in context on our maps.