The political deal which aimed to form the lasting settlement following the 1994 paramilitary ceasefires in Northern Ireland, known as the Good Friday Agreement, was signed on 10 April 1998.
The proposals included plans for a Northern Ireland assembly with a power-sharing executive, new cross-border institutions involving the Irish Republic and a body linking devolved assemblies across the UK with Westminster and Dublin. The Irish Republic also dropped its constitutional claim to the six counties which form Northern Ireland.
There were also controversial proposals on the decommissioning of paramilitary weapons, the future of policing in Northern Ireland, and the early release of paramilitary prisoners.
A copy of the Agreement was posted to every household in Northern Ireland and the Irish Republic and put to referendums the following May, which gave them substantial support by 74% and 94% respectively. The lower amount of support in Northern Ireland was attributed to a significant number of sceptical unionist voters.
Below is a brief outline of the Agreement (divided into three due to the size of the associated PDFs) with links to the actual text.
The body of the document opened with the words: "We, the participants in the multi-party negotiations, believe that the agreement we have negotiated offers a truly historic opportunity for a new beginning."
It referred to "tragedies of the past" that had left "a deep and profoundly regrettable legacy of suffering". The best way to honour those who died or been injured, and their families, was "a fresh start".
The opening statement went on to say that the participants reaffirmed their "total and absolute commitment to exclusively democratic and peaceful means of resolving differences on political issues", and their opposition to any use or threat of force.
They acknowledged the "substantial differences" between them but declared they would work to ensure the success of the Agreement.
Under the section titled "Constitutional Issues", the Agreement stated that the participants acknowledged that "it would be wrong to make any change in the status of Northern Ireland save with the consent of a majority of its people".
It went on to cover the changes to be made to British law and the Irish constitution, from which a territorial claim over Northern Ireland was removed.
The section called Strand One dealt with the establishment and operation of a democratically elected power-sharing assembly in Northern Ireland.
It included safeguards for cross-community participation, such as the allocation of Committee Chairs, Ministers and Committee membership in proportion to party strengths.
Under Strand Two a North/ South Ministerial Council was to bring together those with executive responsibilities in Northern Ireland and the Irish government "on matters of mutual interest".
A British-Irish Council was set up under Strand Three "to promote the harmonious and mutually beneficial development of the totality of relationships among the peoples of these islands".
In practice that means a body with representatives of the British and Irish governments and devolved institutions in Northern Ireland, Scotland and Wales and, if appropriate, elsewhere in the United Kingdom, together with representatives of the Isle of Man and the Channel Islands.
In this section of the Agreement the participants affirmed their "commitment to the mutual respect, the civil rights and the religious liberties of everyone in the community". Measures included the establishment of a new Northern Ireland Human Rights Commission and the incorporation of the European Convention on Human Rights into Northern Ireland law.
Statements then follow on the importance of acknowledging "the suffering of victims of violence" and economic, social and cultural issues.
The section on decommissioning of paramilitary weapons - which has proved to be the most contentious - requires the participants "to use any influence they may have" to achieve decommissioning of all arms "within two years following endorsement in referendums North and South of the agreement and in the context of the implementation of the overall settlement".
The British government is committed to "as early a return as possible to normal security arrangements in Northern Ireland" - subject to the level of threat.
Policing is another controversial area covered in the Agreement, which set up the independent Patten Commission to look at the issue, as well as a parallel commission looking into criminal justice in Northern Ireland.
Equally controversial was the provision in the Agreement for the early release of paramilitary prisoners, as long as the organisations to which they were linked were maintaining a "complete and unequivocal" ceasefire.
The final stages of the Agreement dealt with issues such as a new British-Irish Agreement, the holding of referendums and review procedures following implementation.