August 15th 1998: A bomb explodes in Omagh, killing 29 people, including a woman expecting twins. The IRA ceasefire had been in place for four years, and the Belfast Agreement signed earlier that year.
August 18th 1998: The Real IRA admits responsibility for the attack, blaming the RUC for failing to respond to "clear" warnings. Within weeks Sinn Féin president Gerry Adams calls on all dissident republican groups to disband.
February 25th 1999: Louth publican Colm Murphy is charged with "conspiracy to cause an explosion" and membership of the Real IRA.
October 9th 2000: BBC's Panorama programme names four people suspected of involvement in the bombing. Relatives of four of the Omagh victims said they intended to sue the people named.
March 30th 2001: Michael McKevitt is charged with directing terrorism, a new offence introduced in legislation passed in the aftermath of the bombing.
December 2001: Then police ombudsman Nuala O'Loan releases a highly critical report on the police investigation, describing it as blighted by "hundreds of errors", to the extent that it compromised any later efforts to find the guilty and bring them to court. RUC chief constable Ronnie Flanagan says he will resign and "commit suicide in public" if the accusations are found to be true.
January 23rd 2002: Colm Murphy convicted in the Special Criminal Court.
February 2002: Ronnie Flanagan resigns, and is later appointed as chief police inspector in the UK.
August 6th 2003: McKevitt is convicted of directing terrorism and is serving a 20-year sentence. He later loses an appeal against the conviction, founded on questioning the evidence given by FBI paid informer David Rupert, which constituted a substantial part of the evidence against him.
January 2005: Murphy's conviction is overturned by the Court of Criminal Appeal and a fresh trial ordered, on the basis that Garda notes of an interview in which he allegedly admitted involvement in bombings had been altered. A Supreme Court judgment is awaited on his appeal against a High Court ruling that the re-trial can go ahead.
December 20th 2007: In the North, the only man charged in connection with the bombing, Seán Hoey, is acquitted in a case where the police investigation and prosecution were heavily criticised by the judge, Mr Justice Weir, who said "deliberate and calculated deception" made it impossible for the court to accept anything two key police witnesses had said.
January 2008: Then chief constable of the PSNI, Sir Hugh Orde, says further prosecutions are unlikely.
February 7th 2008: The North's policing board announces a new independent inquiry into police handling of the investigation.
April 7th 2008: The civil case taken by 12 relatives against five named individuals and the Real IRA opens in Belfast, moving later to Dublin to hear evidence from members of the Garda, based on an EU directive on co-operation between courts of member states.
Today: Victims' families continue to call for a full, independent inquiry into both the bombing and the investigation to be carried out on both sides of the Border.