It is uncertain when Okinoerabujima was first settled. It was ruled by the Aji nobility who built numerous gusuku fortifications from the 8th century onwards. From 1266 it was part of Hokuzan, and from 1422 the Ryukyu Kingdom. The island was invaded by samurai from Satsuma Domain during the 1609 Invasion of Ryukyu and its incorporation into the official holdings of Satsuma was recognized by the Tokugawa shogunate in 1624. Satsuma rule was harsh, with the inhabitants of the island reduced to serfdom and forced to raise sugar cane to meet high taxation, which often resulted in famine. The island was subordinate to Tokunoshima from 1616 to 1690, when an independent "daikansho" was established. Throughout the Satsuma period, the island was used as a prison settlement, especially for political offenders, including many members of the Ryukyuan royal family. Saigō Takamori was exiled to Okinoerabujima from 1862 to 1864.