shells, probably also for the exchange of goods with other settlements, was an integral part of the economy. Dating of charcoal remains yielded dates of 1453 (±150 years) and 1113 (±50 years). According to the current state of research, an initial settlement of the Austral Islands can be assumed at the beginning of the second millennium AD. After initial settlement in caves and rock ledges near the coast, a stratified tribal society developed rapidly in settlements near the beach. The structure of the settlements reflected the social order. There were strictly separate dwellings, built of perishable materials, for the aristocracy, the priests, the middle class (artisans, artists), warriors, adolescents and pubescent girls. Due to increasing tribal warfare, the beach settlements were abandoned, probably in the seventeenth or eighteenth century. The inhabitants retreated to heavily fortified settlements in the inland hills, comparable to the Pā of New Zealand. On Rapa Island, for example, 15 such castles have been recorded. The Norwegian archaeological expedition to Easter Island and the eastern Pacific in 1956, led by Thor Heyerdahl, determined an antiquity of between 200 and 300 years for a fortified settlement on Rapa's Morongo Uta hill and dated the Hatututi castle complex of Raivavae to 1700 AD. Numerous wars and probably also overexploitation of natural resources may have drastically reduced the population even before the arrival of Europeans. European exploration and colonization Rurutu was the first of the Austral Islands to be discovered by Europe in 1769. James Cook reached the island, which he named Ohetiroa, during his first voyage to the Pacific on August 14, 1769. After the Endeavour anchored off the island for the night, Cook launched the pinnace the next day under the command of Lieutenant Gore. Naturalist Joseph Banks was also on the ship. A large number of armed warriors were walking along the shore. As Cook had ordered to avoid any risk, the Pinasse returned to the ship without having attempted a landing. The Spaniard Tomás de Gayangos was the first European to reach the island of Raivavae on February 5, 1775 with the ships Águila and Júpiter as part of an expedition to Tahiti initiated by Manuel de Amat y de Junyent.14 The next day Gayangos had a ship leave Tahiti with Lieutenant Benarcosi and two translators, but they were prevented from landing in Mahanatoa Bay by several war canoes. James Cook discovered the island of Tubuai