A chronology of key events in Nigeria dating back from 800 BC. circa 800 BC - Jos plateau settled by Nok - a neolithic and iron age civilisation. circa 11th century onwards - Formation of city states, kingdoms and empires, including Hausa kingdoms and Borno dynasty in north, Oyo and Benin kingdoms in south. 1472 - Portuguese navigators reach Nigerian coast. 16-18th centuries - Slave trade: Millions of Nigerians are forcibly sent to the Americas. 1809 - Single Islamic state - Sokoto caliphate - is founded in north. 1830s-1886 - Civil wars plague Yorubaland, in the south. 1850s - British establish presence around Lagos. 1861-1914 - Britain consolidates its hold over what it calls the Colony and Protectorate of Nigeria, governs by "indirect rule" through local leaders. 1922 - Part of former German colony Kamerun is added to Nigeria under League of Nations mandate. 1960 - Independence, with Prime Minister Sir Abubakar Tafawa Balewa leading a coalition government. 1962-63 - Controversial census fuels regional and ethnic tensions. 1966 January - Balewa killed in coup. Major-General Johnson Aguiyi-Ironsi heads up military administration. 1966 July - Ironsi killed in counter-coup, replaced by Lieutenant-Colonel Yakubu Gowon. 1967 - Three eastern states secede as the Republic of Biafra, sparking bloody civil war. 1970 - Biafran leaders surrender, former Biafran regions reintegrated into country. 1975 - Gowon overthrown, flees to Britain, replaced by Brigadier Murtala Ramat Mohammed, who begins process of moving federal capital to Abuja. Obasanjo - first time round 1976 - Mohammed assassinated in failed coup attempt. Replaced by his deputy, Lieutenant-General Olusegun Obasanjo, who helps introduce American-style presidential constitution. 1979 - Elections bring Alhaji Shehu Shagari to power. 1983 January - The government expels more than one million foreigners, mostly Ghanaians, saying they had overstayed their visas and were taking jobs from Nigerians. The move is condemned abroad but proves popular in Nigeria. 1983 August, September - Shagari re-elected amid accusations of irregularities. 1983 December - Major-General Muhammad Buhari seizes power in bloodless coup. 1985 - Ibrahim Babangida seizes power in bloodless coup, curtails political activity. 1993 June - Military annuls elections when preliminary results show victory by Chief Moshood Abiola. 1993 August - Power transferred to Interim National Government. Abacha years 1993 November - General Sani Abacha seizes power, suppresses opposition. 1994 - Abiola arrested after proclaiming himself president. 1995 - Ken Saro-Wiwa, writer and campaigner against oil industry damage to his Ogoni homeland, is executed following a hasty trial. In protest, European Union imposes sanctions until 1998, Commonwealth suspends Nigeria's membership until 1998. 1998 - Abacha dies, succeeded by Major-General Abdulsalami Abubakar. Chief Abiola dies in custody a month later. 1999 - Parliamentary and presidential elections. Olusegun Obasanjo sworn in as president. 2000 - Adoption of Islamic, or Sharia, law by several northern states in the face of opposition from Christians. Tension over the issue results in hundreds of deaths in clashes between Christians and Muslims. 2001 - Tribal war in Benue state, in eastern-central Nigeria, displaces thousands of people. In October, army soldiers sent to quash the fighting kill more than 200 unarmed civilians, apparently in retaliation for the abduction and murder of 19 soldiers. 2001 October - Nigerian President Olusegun Obasanjo, South African President Mbeki and Algerian President Bouteflika launch New Partnership for African Development, or Nepad, which aims to foster development and open government and end wars in return for aid, foreign investment and the lifting of trade barriers to African exports. Ethnic violence 2002 February - Some 100 people are killed in Lagos in clashes between Hausas from mainly-Islamic north and ethnic Yorubas from predominantly-Christian southwest. 2002 November - More than 200 people die in four days of rioting stoked by Muslim fury over the planned Miss World beauty pageant in Kaduna in December. The event is relocated to Britain. 2003 12 April - First legislative elections since end of military rule in 1999. Polling marked by delays, allegations of ballot-rigging. President Obasanjo's People's Democratic Party wins parliamentary majority. Obasanjo re-elected 2003 19 April - First civilian-run presidential elections since end of military rule. Olusegun Obasanjo elected for second term with more than 60% of vote. Opposition parties reject result. EU poll observers cite "serious irregularities". 2003 July - Nationwide general strike called off after nine days after government agrees to lower recently-increased fuel prices. 2003 August - Inter-communal violence in the Niger Delta town of Warri kills about 100 people, injures 1,000. 2003 September - Nigeria's first satellite, NigeriaSat-1, launched by Russian rocket. 2004 January - UN brokers talks between Nigeria and Cameroon about disputed border. Both sides agree to joint security patrols. 2004 May - State of emergency is declared in the central Plateau State after more than 200 Muslims are killed in Yelwa in attacks by Christian militia; revenge attacks are launched by Muslim youths in Kano. Trouble in the south 2004 August-September - Deadly clashes between gangs in oil city of Port Harcourt prompts strong crackdown by troops. Rights group Amnesty International cites death toll of 500, authorities say about 20 died. 2005 July - Paris Club of rich lenders agrees to write off two-thirds of Nigeria's $30bn foreign debt. 2006 January onwards - Militants in the Niger Delta attack pipelines and other oil facilities and kidnap foreign oil workers. The rebels demand more control over the region's oil wealth. 2006 February - More than 100 people are killed when religious violence flares in mainly-Muslim towns in the north and in the southern city of Onitsha. 2006 April - Helped by record oil prices, Nigeria becomes the first African nation to pay off its debt to the Paris Club of rich lenders. 2006 May - The Senate rejects proposed changes to the constitution which would have allowed President Obasanjo to stand for a third term in 2007. Bakassi deal 2006 August - Nigeria cedes sovereignty over the disputed Bakassi peninsula to neighbouring Cameroon under the terms of a 2002 International Court of Justice ruling. A special transitional arrangement for the Nigerian civilian administration will be in place for five years. 2006 October - Spiritual leader of Nigeria's millions of Muslims, the Sultan of Sokoto, is killed in a plane crash, the country's third major civilian air disaster in a year. 2007 April - Umaru Yar'Adua of the ruling People's Democratic Party is proclaimed winner of the presidential election. 2007 September - The rebel Movement for the Emancipation of the Niger Delta (Mend) threatens to end a self-imposed ceasefire and to launch fresh attacks on oil facilities and abductions of foreign workers. 2007 November - Suspected Nigerian militants kill 21 Cameroon soldiers in Bakassi peninsula. Nigerian senate rejects Nigeria-Cameroon agreement for hand-over of Bakassi peninsula to Cameroon. 2007 December - Anti-corruption chief Nuhu Ribadu is sidelined, but a high-profile graft-related arrest follows soon after. Oil prices soar 2008 January - Oil trades at $100 a barrel for the first time, with violence in oil producing countries such as Nigeria and Algeria helping to drive up prices. 2008 February - Mend leaders Henry Okah and Edward Atata extradited from Angola on suspicion of involvement in attacks on oil companies. Report that Okah was subsequently killed in custody proved to be untrue. Tribunal upholds election of Umaru Yar'Adua as president following challenge by rivals who wanted the vote annulled because of vote rigging. 2008 April - Two former health ministers and a daughter of President Olusegun Obasanjo are among 12 top health officials charged with embezzling around 470m naira (4m dollars) of public health funds. Oil production cut by about half as a result of strike action and attacks on pipelines by militants; problems in Nigeria help keep world oil prices at record highs. 2008 August - Following agreement reached in March, Nigeria finally hands over the Bakassi peninsula to Cameroon, ending a long-standing dispute. Iran agrees to share nuclear technology with Nigeria to help it increase its generation of electricity. 2008 September - Militants in the Niger Delta step up their attacks on oil installations, in response to what they describe as unprovoked attacks by the military on their bases. Oil prices fall 2008 October - The government announces major budget cuts following steep falls in the price of oil. 2008 November - At least 200 people are killed during clashes between Christians and Muslims in the central Nigerian town of Jos. 2009 January - The main militant group in Niger Delta, Mend, calls off four-month cease-fire after army attacks camp of an allied group. 2009 March - Nineteen opposition parties unite to form a "mega-party" to compete against the governing People's Democratic Party in elections due in 2011. 2009 May - Niger Delta militant group Mend rejects government offer of amnesty and declares offensive against Nigerian military. 2009 July - Hundreds die in northeastern Nigeria after the Boko Haram Islamist movement launches a campaign of violence in a bid to have Sharia law imposed on the entire country. Security forces storm Boko Haram's stronghold and kill the movement's leader. Government frees the leader of the Niger Delta militant group Mend, Henry Okah, after he accepts an amnesty offer. 2009 August - Two-month offer of a government amnesty for Niger Delta militants comes into force. Yar'Adua absent 2009 November - President Yar'Adua travels to Saudi Arabia to be treated for a heart condition. His extended absence triggers a constitutional crisis and leads to calls for him to step down. 2010 January - At least 149 people are killed during two days of violence between Christian and Muslim gangs in the central city of Jos. 2010 March - More than 120 people are killed in clashes between Muslims and Christians in the flashpoint city of Jos. Jonathan president 2010 May - President Umaru Yar'Adua dies after a long illness. Vice-president Goodluck Jonathan, already acting in Yar'Adua's stead, succeeds him. 2010 September - Presidential elections set for 22 January 2011. 2010 October - Nigeria marks 50 years of independence. Credit: BBC