Traditionally, political power in Samoa was held by matai (chiefs), whose positions were generally inherited, with power can earn positions. The matai survives to the present day, but was changed during the colonial and post-colonial periods. Political drama characterized the 19th century in Samoa, during which matai-lead governments formed and reformed, often with support from traders, missionaries, and other foreigners. In 1899 the colonial power of Germany, Great Britain, and the United States resolved this for their own purposes by signing a treaty granting Germany control of Western Samoa and the United States control of Eastern (American) Samoa. Western Samoa, however, was occupied by New Zealand during World War I and was a colony of that country until it gained independence in 1962. In the 1920s the Mau movement, advocating non-payment of tax and whose main goal was independence, was formed. The movement was suppressed by New Zealand troops in the late 1920s but it remains a symbol of nationalism to the present day.