Between the 7th and the 6th century B.C., migrations started from Central Polynesia (Fiji Islands, Tonga and Samoa) towards Eastern Polynesia, currently comprising the Society Islands, the Marquesas, the Tuamotus, the Gambier Islands, the Austral Islands, Hawaii and Easter Island.
Different reasons may have led those people to migrate: one of the most accredited reason is  demographic growth, which in turn caused devastating economic effects and political tensions.
Polynesians were great seafarers specialized in the construction of large outrigger canoes used in offshore navigations and war expeditions, during which they could rely on their vast knowledge of geography and astronomy.