Many important hominid fossils have been found in Tanzania. In the Stone and Bronze Age, prehistoric migrations into Tanzania included Southern Cushitic speakers similar to modern day Iraqw people who moved south from present-day Ethiopia;[13] Eastern Cushitic people who moved into Tanzania from north of Lake Turkana about 2,000 and 4,000 years ago; and the Southern Nilotes, including the Datoog, who originated from the present-day South Sudan–Ethiopia border region between 2,900 and 2,400 years ago.[13]: page 18  These movements took place at about the same time as the settlement of the Mashariki Bantu from West Africa in the Lake Victoria and Lake Tanganyika areas.[13][14] In the late 19th century, the mainland came under German rule as German East Africa, and this was followed by British rule after World War I when it was governed as Tanganyika, with the Zanzibar Archipelago remaining a separate colonial jurisdiction. Following their respective independence in 1961 and 1963, the two entities merged in 1964 to form the United Republic of Tanzania.[15] Tanganyika joined the British Commonwealth and Tanzania remains a member of the Commonwealth as a unified republic.[16]