A chronology of key events:
1498 - Portuguese explorer Vasco da Gama visits Tanzanian coast.
Father of the nation
First president Julius Nyerere was influential in Africa's independence movement
1506 - Portuguese succeed in controlling most of the East African coast.
1699 - Portuguese ousted from Zanzibar by Omani Arabs.
1884 - German Colonisation Society begins to acquire territory on the mainland.
1886 - Britain and Germany sign an agreement allowing Germany to set up a sphere of influence over mainland Tanzania, except for a narrow piece of territory along the coast which stays under the authority of the sultan of Zanzibar, while Britain enjoys a protectorate over Zanzibar.
1905-06 - Indigenous Maji Maji revolt suppressed by German troops.British rule
1916 - British, Belgian and South African troops occupy most of German East Africa.
1919 - League of Nations gives Britain a mandate over Tanganyika - today's mainland Tanzania.
1929 - Tanganyika African Association founded.
Tanzania has many natural wonders, some of which are under threat
1946 - United Nations converts British mandate over Tanganyika into a trusteeship.
1954 - Julius Nyerere and Oscar Kambona transform the Tanganyika African Association into the Tanganyika African National Union.Independence
1961 - Tanganyika becomes independent with Julius Nyerere as prime minister.
1962 - Tanganyika becomes a republic with Nyerere as president.
1963 - Zanzibar becomes independent.
1964 - Sultanate of Zanzibar overthrown by Afro-Shirazi Party in a violent, left-wing revolution; Tanganyika and Zanzibar merge to become Tanzania, with Nyerere as president and the head of the Zanzibar government and leader of the Afro-Shirazi Party, Abeid Amani Karume, as vice-president.
1967 - Nyerere issues the Arusha Declaration, which calls for egalitarianism, socialism and self-reliance.
1977 - The Tanganyika African National Union and Zanzibar's Afro-Shirazi Party merge to become the Party of the Revolution, which is proclaimed as the only legal party.
1978 - Ugandans temporarily occupy a piece of Tanzanian territory.
1979 - Tanzanian forces invade Uganda, occupying the capital, Kampala, and help to oust President Idi Amin.Multi-party politics
1985 - Nyerere retires and is replaced by the president of Zanzibar, Ali Mwinyi.
1992 - Constitution amended to allow multi-party politics.
1995 - Benjamin Mkapa chosen as president in Tanzania's first multi-party election.
US embassies were hit in Nairobi and Dar es Salaam by the al-Qaeda terror group
1998 August - Bomb attacks on US embassies in Tanzania and Kenya.
1999 October - Julius Nyerere dies.
2000 - Mkapa elected for a second term, winning 72% of the vote.
2001 26 January - Tanzanian police shoot dead two people in Zanzibar while raiding the offices in Zanzibar town of the Civic United Front (CUF) party.
CUF chairman Ibrahim Lipumba charged with unlawful assembly and disturbing the peace.Zanzibar violence
2001 27-28 January - At least 31 people are killed and another 100 arrested in Zanzibar in protests against the government's banning of opposition rallies calling for fresh elections; Tanzanian government sends in troop reinforcements.
2001 March - Governing Chama Cha Mapinduzi (CCM), and main opposition in Zanzibar, CUF, agree to form joint committee to restore calm and to encourage return of refugees from Kenya.
2001 April - Tens of thousands of opposition supporters march through the commercial capital, Dar es Salaam, in the first major joint demonstration by opposition parties in decades.
2001 July - Huge new gold mine, Bulyanhulu, opens near northern town of Mwanza, making Tanzania Africa's third largest producer of gold.
Port of Dar es Salaam
- Founded in 1862 by sultan of Zanzibar
- Capital of German East Africa, 1891-1916
- Capital of Tanzania 1964-74
- Population: 2.3 million
2001 November - Presidents of Tanzania, Uganda and Kenya launch regional parliament and court of justice in Arusha to legislate on matters of common interest such as trade and immigration.
2001 December - Britain approves controversial deal to sell military air traffic control system to Tanzania. Critics say it is a waste of money.
2002 June - Nearly 300 killed in Tanzania's worst train disaster after passenger train loses power and rolls into freight train at high speed.
2002 August - Opposition criticises president for ordering presidential jet costing $21m (£14m).
2005 March-April - Political violence in semi-autonomous Zanzibar ahead of voter registration for October poll.
2005 October - Governing CCM wins Zanzibar elections. Opposition CUF claims vote-rigging and announces an indefinite boycott of Zanzibar's parliament.Kikwete elected
2005 December - Jakaya Kikwete, foreign minister and ruling CCM candidate, wins presidential elections. He replaces Benjamin Mkapa, who retires after a decade at the helm.
2006 April - High Court outlaws traditional practice of entertaining candidates during elections. Critics of "Takrima" - the giving of tips - said it encouraged corruption.
2006 June - Visiting Chinese Prime Minister Wen Jiabao, on his seven-nation African tour to secure energy deals and strengthen economic ties, signs agreements to help Tanzania's health, transport and communications sectors.
2006 August - The African Development Bank announces the cancellation of more than $640m of debt owed by Tanzania, saying it was impressed with Tanzania's economic record and the level of accountability of public finance.
2007 January - Britain's Serious Fraud Office visits Tanzania to probe the controversial purchase of an air traffic control system in 2001. A British paper reports that the British defence company, BAE Systems, allegedly paid a Tanzanian middleman a commission of $12m to win the order.
2007 July - Former US president Bill Clinton launches a programme aimed at making subsidised malaria drugs available in a pilot scheme that could spread to the rest of Africa.
2008 January - Central Bank Governor Daudi Ballali is sacked after an international audit finds the bank made improper payments of more than $120m (£60m) to local companies.Scandal
2008 February - President dissolves his cabinet following a corruption scandal which forced the premier and two ministers to resign.
2009 November - Opposition party in Zanzibar, the CUF, ends boycott of the island's parliament ahead of upcoming elections.
2010 July - Tanzania joins its neighbours in forming a new East African Common Market, intended to integrate the region's economy.
2010 September - President Kikwete says construction of highway through Serengeti game reserve will go ahead, despite criticism from environmental experts.
2010 October - President Kikwete wins re-election.
2010 December - Britain's largest arms manufacturer, BAE Systems, is fined over a controversial contract to supply Tanzania with a radar system.
2011 January - Two killed as police try disperse demonstrators demanding release of Chadema opposition party leader Freeman Mbowe, detained ahead of a rally against government corruption.
2011 July - British arms and aircraft firm BAE Systems admits setting up sham compensation arrangements worth £8m for the sale of an overly-complex air-traffic control system to Tanzania in 1999, and agrees to pay Tanzania £30m in compensation.
2012 March - The Statoil and Exxon Mobil oil exploration companies make the biggest offshore discovery yet of gas reserves off the coast of Tanzania. The Zafarani field is close to the region off the coast of Mozambique where even larger deposits of gas are being developed by Anadarko and ENI.
2012 May - President Jakaya Kikwete sacks six ministers after the inspector of public finances notes the "rampant misuse of funds" in at least seven ministries. The ministers of finance, energy, tourism, trade, transport and health lose their jobs.
2012 August - Tanzania confirms 36 Iranian oil tankers have been using Tanzanian flags to evade US and EU economic sanctions on Iran's crude oil exports. The US warns Tanzania that it could face sanctions unless the flag operation stops.
2012 October - Police arrest 126 people over attacks on five churches in Dar es Salaam. Muslims vandalised and torched the churches after a Christian boy had allegedly urinated on a copy of the Koran.
2013 March - New Chinese president Xi Jinping visits as part of a tour of Africa.
2013 May - A bomb attack on a new Roman Catholic church in Arusha kills two and injures dozens.