The African Great Lakes nation of Tanzania dates formally from 1964, when it was formed out of the union of the much larger mainland territory of Tanganyika and the coastal archipelago of Zanzibar. The former was a colony and part of German East Africa from the 1880s to 1919’s when, under the League of Nations, it became a British mandate. It served as a British military outpost during World War II, providing financial help, munitions, and soldiers. In 1947, Tanganyika became a United Nations Trust Territory under British administration, a status it kept until its independence in 1961. The island of Zanzibar thrived as a trading hub, successively controlled by the Portuguese, the Sultanate of Oman, and then as a British protectorate by the end of the nineteenth century. Julius Nyerere, independence leader and "baba wa taifa" for Tanganyika (father of the Tanganyika nation), ruled the country for decades, while Abeid Amaan Karume, governed Zanzibar as its president and Vice President of the United Republic of Tanzania. Following Nyerere's retirement in 1985, various political and economic reforms began. He was succeeded in office by President Ali Hassan Mwinyi. Prehistory Early Stone Age Tanzania is home to some of the oldest hominid settlements unearthed by archaeologists. Prehistoric stone tools and fossils have been found in and around Olduvai Gorge in northern Tanzania, an area often referred to as "The Cradle of Mankind". Acheulian stone tools were discovered there in 1931 by Louis Leakey, after he had correctly identified the rocks brought back by Hans Reck to Germany from his 1913 Olduvai expedition as stone tools. The same year, Louis Leakey found older, more primitive stone tools in Olduvai Gorge. These were the first examples of the oldest human technology ever discovered in Africa, and were subsequently known throughout the world as Oldowan after Olduvai Gorge. The first hominid skull in Olduvai Gorge was discovered by Mary Leakey in 1959, and named Zinj or Nutcracker Man, the first example of Paranthropus boisei, and is thought to be more than 1.8 million years old. Other finds including Homo habilis fossils were subsequently made. At nearby Laetoli the oldest known hominid footprints, the Laetoli footprints, were discovered by Mary Leakey in 1978, and estimated to be approximately 3.6 million years old and probably made by Australopithecus afarensis. The oldest hominid fossils ever discovered in Tanzania also come from Laetoli and are the 3.6 to