The Irish Republican Army (IRA) paramilitary movement declared that it would put down its arms from 4 pm (0400 GMT) on Thursday.
A statement from the movement said it would put an end to its armed struggle and devote efforts towards peaceful solutions.
The following are some key facts about Northern Ireland.
Area: 14,000 square km.
It neighbors the Republic of Ireland. Great Britain lies across the Irish Sea to the east.
Religion: According to the 1991 statistics, 50.7 percent of residents claimed themselves Protestant and 38.4 percent Roman Catholic.
Government and Politics: Northern Ireland is part of the United Kingdom. Queen Elizabeth II is its constitutional monarchy as titular head of state.
Northern Ireland elects a new 108-seat Assembly to operate a range of limited home-rule power. But the assembly inherits its power from London only once a peace accord is fully implemented.
There are nine political parties. The four main parties are the Ulster Unionist Party (UUP), the Social Democratic and Labour Party (SDLP), the Democratic Unionist Party (DUP), hard-line unionist party, and Sinn Fein, the political wing of the IRA.
Economy: Gross Domestic Product (GDP) per head was 13,490 US dollars in 1995.
Unemployment is about 7 percent.
Services account for 74 percent of economic output, while manufacturing makes up 18 percent.
History: Ireland was part of the United Kingdom for centuries. After decades of civil war, Ireland won its independence in 1922, but Britain negotiated to keep the six counties in the northeast dominated by Protestants.
In 1969, guerrilla fighting between the IRA and loyalist groups began, starting a period that became known as the "troubles." Since then, some 3,600 people have died as a direct result of the conflict.
In a peace-seeking declaration in December 1993, the British government said it would not block an end to British rule if a majority wanted it, and offered Sinn Fein a seat at party talks.
They met for the first time in 70 years in 1994.
The IRA and loyalist militias called ceasefires beginning in 1994, moves which paved the way for the peace accord.
Peace Accord: The peace agreement says that there will be no change in Northern Ireland's constitutional status without the consent of the majority. Ireland for the first time agreed to give up legal claim to Northern Ireland.