Tuvalu was probably settled as part of the backwash by which the outliers were populated after the main eastward historical wave of Polynesian migration. Prehistoric Samoan cultural influence was undoubtedly strong, as the linguistic affiliation suggests, but this influence also may have been retrospectively enhanced by religious and administrative links in the modern era. Precontact history is difficult to reconstruct, since there has been very little archaeological investigation. Moreover, local traditions, while essential for a proper historical understanding, often contradict each other as political charters for descent groups within local status hierarchies. Different island communities claim different founding ancestors, some autochthonous and some hailing from Samoa, Tonga, East Uvea, and/or Kiribati. Funafuti is also cited as the immediate homeland of some of the other islands. Evidence from material culture, comparative linguistics, and culture history all indicate relatively recent settlement dates from the fourteenth to the eighteenth centuries. Skeletal remains from Vaitupu, however, may point to a slightly longer time scale of 500 to 800 years. The first sighting of a Tuvaluan island (Nui) by a Westerner ( ppaalagi ) was probably made by the Spanish explorer Mendaña, in 1568, but it was not until the early nineteenth century that real contact began. Explorers, traders, and whalers charted the group and, as the century wore on, White traders and beachcombers settled on some of the islands. The most intensive phase of contact began in 1865 with the arrival of (mainly) Samoan teachers and pastors sent by the London Missionary Society. Their version of evangelical and congregationalist Protestantism continues to be a major sociocultural influence to the present day, though the Tuvalu church is now autonomous. Other churches and religions have obtained footholds but remain minorities in a society that emphasizes individual conformity with communal ideology. In 1892, Great Britain declared a protectorate over what were then called the Ellice Islands, which was administered jointly with the Gilbert Islands (as a colony after 1916) until 1975. While the Gilberts were occupied by Japanese troops during World War II, Tuvalu became a forward base for U.S. forces. It largely escaped the direct effects of battle but the presence of large numbers of servicemen on Nanumea, Nukufatau, and Funafuti had a substantial impact. As Great Britain moved to divest itself of its Pacific possessions in the 1960s, Tuvaluans decided against remaining tied to the Gilbertese (who were culturally different, negatively stereotyped, and much more numerous). They seceded in 1975 and became fully independent in 1978, retaining ties to Great Britain through membership in the Commonwealth.