June 1993 – Presidential elections in Nigeria are judged to be essentially free and fair. At the time, Nigeria is managed by the Provisional Ruling Council, a 32-member organ comprised of military officers and civilians which rules by decree following the suspension of the 1979 Constitution.
June 1993 – The military, led by acting president General Ibrahim Babangida, annuls election results. Polls indicate that the vote had been won by wealthy businessman Moshood Abiola, who earned an estimated 58 percent of the vote. Riots follow, in which 100 people die. Babangida eventually cedes power to a transitional civilian government pending planned elections in 1994.
November 1993 – General Sani Abacha forces out the acting government and establishes a ruling regime. Abacha quickly dissolves the transitional civilian government, replaces it with military officers, and bans political parties.
May 1994 – Prior to elections for a Constitutional Conference, the Abacha regime cracks down on the opposition, resulting in a largely boycotted election. Two weeks later, Abiola declares himself the rightful president of Nigeria and immediately goes into hiding. Abiola is later arrested and jailed for treason in June.
July 1994 – Petroleum workers launch a labor strike against the government to demand that Abiola be released and declared president. The strike spreads to other unions and paralyzes much of Nigeria.
August 1994 – The Abacha regime imposes military control over unions and jails their leaders. The strike ends and the government begins a new crackdown on opponents.
June/July 1995 – Claiming it had uncovered a coup plot, the Abacha regime secretly arrests, convicts, and sentences 40 alleged ringleaders. Opposition sympathizers are also caught up in the dragnet of arrests.
October 1995 – Abacha announces a three-year timetable for a return to democratic government.
December 1997 – Disillusioned voters boycott local elections after it becomes clear that Abacha has co-opted the election process in order to entrench his personal power; less than 10 percent of the electorate goes to the polls. By the end of December, the Abacha regime rounds up the leaders of another suspected coup. Arrests in this latest alleged coup top 60 within a month.
June 1998 – Abacha dies. General Abdulsalam Abubakar assumes leadership of Nigeria. Abubakar institutes a number of government reforms, frees political prisoners, and promises to return Nigeria to democratic rule.
July 1998 – A day before his scheduled release, Abiola dies in prison of an apparent heart attack, sparking violent riots.
August 1998 – Abubakar establishes the Independent National Electoral Commission to conduct elections and formalizes a timetable by which the country would return to civilian rule.
December 1998 to February 1999 – The electoral commission successfully conducts local, state, federal, and presidential elections across Nigeria.
February 1999 – Retired General Olusegun Obasanjo is elected president with 63 percent of the vote, defeating Olu Falae, who garnered only 37 percent. Obasanjo, who had governed Nigeria as a military leader in the 1970s, was at that point the only military ruler in Nigeria's history to have ceded power to a civilian government, and had only recently been freed from prison after being arrested during the alleged 1995 coup.
May 1999 – Obasanjo is inaugurated as president, ending 16 years of military rule. Moments before taking the oath of office, Obasanjo is presented a copy of the newly enacted Constitution, finalized in secret by the outgoing Abubakar regime.
June 1999 – In a special closed legislative session, congressmen debate whether to increase their housing allowances to $140,000 per year. The debate comes shortly after a divisive campaign by teachers and civil servants to institute a $30-per-month minimum wage.
June 1999 – In his first speech to a joint session of Parliament, Obasanjo pledges to make anti-corruption the centerpiece of his administration. The first bill he sends to the National Assembly targets corruption, but after passing through the House, the bill languishes.
July 1999 – Ibrahim Salisu Buhari, the first speaker of the House under Obasanjo, resigns after less than two months in office when it is discovered that he lied about his academic background and age, which would have constitutionally disqualified him from the position. Buhari pleads guilty to forgery and perjury in connection to the scandal, and is eventually fined the equivalent of US$20. He is pardoned less than a year later.
June 2000 – The National Assembly finally passes the Independent Corrupt Practices and Other Related Offences Commission Act, establishing the Independent Corrupt Practices and Other Related Offences Commission (ICPC) to enforce anti-corruption measures in Nigeria. The commission is inaugurated in September.
July 2000 – A government investigation uncovers what it characterizes as inflated procurement contracts in the National Assembly, some of them awarded to companies in which legislators had a financial interest. High-level officials are implicated by the investigation, including Senate President Chuba Okadigbo and Senate Deputy President Alhaji Haruna Abubakar, who both collected substantial "welfare" packages from the government.
August 2000 – Okadigbo is impeached for corruption and misappropriation of funds. After his impeachment, Okadigbo is indicted for spending public money on cars and car furnishings. Following intense media pressure, Okadigbo resigns in October. The indictment is eventually dropped.
October 2000 – President Obasanjo is accused by eight House members of bribing them to help oust Speaker of the House Ghali Na'Abba, who Obasanjo had attacked for his corruption. The legislators dramatically unload the alleged bribes on the House floor. Obasanjo strongly denies the charges and calls for an investigation into the matter.
October 2000 – Construction begins on one of Obasanjo's pet projects—a modern sports stadium in Abuja. The estimated cost of US$380 million exceeds the combined budgets for national health and education, and the actual costs eventually spiral hundreds of millions of dollars over budget.
February 2002 – A government anti-corruption commission issues its first indictment of a high-level government official, accusing Justice Garba Abdullahi of demanding a US$9,000 bribe from a businessman in order to reverse an adverse ruling.
April 2002 – The House unanimously strikes down a measure signed into law that would have outlawed the formation of new political parties ahead of the 2003 presidential election, claiming that Obasanjo had inserted new language into the bill after it had been submitted to him.
August 2002 – The National Assembly threatens to impeach Obasanjo if he refuses to resign, accusing him of 17 separate indictable offenses including incompetence, disregard for the rule of law, and corruption. Obasanjo refuses to resign.
September 2002 – The ICPC obtains its first conviction, sentencing local government chairman Emmanuel Egwuba to three years in prison for awarding a contract without budgetary approval.
January 2003 – Auditor-General Vincent Azie submits a 300-page annual report, covering the 2001 financial year. The report chronicles corruption in Nigeria, including a number of suspicious payments and honoraria to politicians, and criticizes all branches of government. The following month, Obasanjo fires Azie.
February 2003 – The National Assembly passes a bill replacing the ICPC with a less-powerful anti-corruption entity. Obasanjo subsequently vetoes the measure. The Assembly tries to override the veto in May, a move which is ruled illegal by the chief judge of the Federal High Court, who affirms the Corrupt Practices and Other Related Offenses Act of 2000.
April 2003 – In the first civilian-run presidential elections since the end of military rule, Obasanjo wins re-election with 62 percent of the vote, defeating former military ruler Muhammadu Buhari, who had seized power by coup in 1983. The opposition rejects the result, and international observers note that serious irregularities occur during balloting.
November 2003 – The government releases its report on the Nigeria Airways investigation, commissioned by Obasanjo in 2001 and shelved since May 2002. The report details the systematic looting of the once-prosperous airline, and implicates 90 people in its downfall. The report recommends that the government prosecute several individuals and seek to recover US$400 million looted by companies and government officials.
December 2003 – After the ICPC announces that it is probing top government officials for allegedly accepting bribes from a French firm, Sagem SA, Obasanjo fires Labor Minister Hussaini Zannuwa Akwanga. At the end of the month, prosecutors charge five people, including Akwanga and two other former ministers, with taking bribes from Sagem, which won a US$214 million contract to produce national identity cards. As of March 25, 2004, the case was pending.