Shortly after independence, Tanganyika and Zanzibar merged to form the nation of Tanzania in 1964. One-party rule came to an end in 1995 with the first multi-party elections held in the country since the 1970s.
Arab traders first began to colonize the area in 700. Portuguese explorers reached the coastal regions in 1500 and held some control until the 17th century, when the sultan of Oman took power. With what are now Burundi and Rwanda, Tanganyika became the colony of German East Africa in 1885. After World War I, it was administered by Britain under a League of Nations mandate and later as a UN trust territory.
Although not mentioned in old histories until the 12th century, Zanzibar was always believed to have had connections with southern Arabia. The Portuguese made it one of their tributaries in 1503 and later established a trading post, but they were driven out of East Africa by Arabs in 1698. Zanzibar was declared independent of Oman in 1861 and, in 1890 it became a British protectorate.
Tanganyika became independent on Dec. 9, 1961; Zanzibar on Dec. 10, 1963. On April 26, 1964, the two nations merged into the United Republic of Tanganyika and Zanzibar. The name was changed to Tanzania six months later.
An invasion by Ugandan troops in Nov. 1978 was followed by a counterattack in Jan. 1979, in which 5,000 Tanzanian troops were joined by 3,000 Ugandan exiles opposed to President Idi Amin. Within a month, full-scale war developed. Tanzanian president Julius Nyerere kept troops in Uganda in open support of former Ugandan president Milton Obote, despite protests from opposition groups, until the national elections in Dec. 1980.
In Nov. 1985, Nyerere stepped down as president. Ali Hassan Mwinyi, his vice president, succeeded him. Running unopposed, Mwinyi was elected president in October. Shortly thereafter plans were announced to study the benefits of instituting a multiparty democracy, and in Oct. 1995 the country's first multiparty elections since independence took place.
On Aug. 7, 1998, the U.S. embassy in Dar es Salaam was bombed by terrorists, killing ten. The same day an even more devastating explosion destroyed the U.S. embassy in neighboring Kenya.
After taking office in 1995, President Benjamin William Mkapa sought to increase economic productivity while dealing with serious pollution problems and deforestation. With more than one million people infected with HIV, AIDS care and prevention have been major public health issues. On foreign policy, Tanzania has taken a leading diplomatic role in East Africa, hosting peace talks for the factions fighting in neighboring Burundi. The UN International Criminal Tribunal for Rwanda (ICTR) is located in the town of Arusha. In Oct. 2000, Mkapa was reelected, and in December 2005, Jakaya Mrisho Kikwete was elected President of Tanzania.