Every summer in Northern Ireland is the marching season when the three main Protestant marching orders (the Orange Order, the Apprentice Boys, the Royal Black Institution) hold parades to commemorate important events from the past. The most important of those three orders by far is the Orange Order (every Northern Ireland premier between 1922 and 1972 was a member) and the most important parade is held annually on July 12th to commemorate King William of Orange's victory over the forces of King James II in the Battle of the Boyne in 1690 that guaranteed Protestantism in the United Kingdom and also kept Catholicism as a minority religion. The Orange Order was founded in 1795 to fight the Defenders, a Catholic organization, for control of areas in Ulster. What happens on the Twelfth is a good barometer of the atmospherics in the peace process and ethnic relations in the province.
In the first years of the peace process following the IRA and loyalist ceasefires of August/September and October 1994, the twelfth was a kind of proxy contest for the various paramilitary organizations to keep them focused and not otherwise disturbing their ceasefires. Various IRA or former IRA leaders became heads of local Sinn Fein concerned citizens groups across Northern Ireland organized to prevent parades by the marching orders in their areas. Eventually a quango or quasi non-governmental organization called the Parades Commission was organized to decided where and under what conditions parades could be held by both unionists and nationalists. Everyone had to have a permit to hold a parade and to get the permit they had to submit basic information on parade route, time, marshaling, music, etc. This was after huge annual confrontations at the Drumcree Church outside of Portadown clearly established the need for such an institution. If I were a standup comedian in Northern Ireland I would ask, "Why do the same two teams get to go to the big game every year, year after year?" Every year it was the Portadown Orange Order versus the Garvaghy Road Residents Committee. After major disputes in 1995, 1996, and 1997 that helped to elect David Trimble leader of the Ulster Unionist Party in 1995, the march was finally banned by the newly-formed Parades Commission in 1998.
Gradually during the last decade attention on the Twelfth has shifted away from Drumcree, which looked like a World War I battlefield with its trenches, to North Belfast and Derry. If the loyalists were feeling neglected by the peace process they rioted on the Twelfth in East Belfast and North Belfast. In recent years since the peace process was finally bedded down in May 2007 it has been the turn of dissident republicans opposed to the Good Friday Agreement of April 1998 who have used the riots as a cover to target policemen.
The parades controversies have cost the province hundreds of millions of dollars/pounds sterling in lost business investments and tourism revenues as both investors and tourists have stayed away. Every year there was a major exodus of the middle class to Ireland, Scotland, and other destinations in a bid to escape the annual riots and drunken behavior. Potentially the parades, if held peacefully and marketed properly by the joint tourism board for the Republic and Northern Ireland, have the potential to generate a lot of tourism and accompanying money to Northern Ireland.
This year there were riots at flash points where Protestant and Catholic neighborhoods intersect in North Belfast. Some ten shots were fired at police. Here is a link to an article with embedded video describing the situation. During the period from 1998 to 2007 Northern Ireland was trapped in a situation that was in between pre-Troubles normality and the situation that prevailed before the IRA began its insurgency in February 1971. It was like 1968-70 in terms of casualties from political violence. Now the peace process is secure, but on every Twelfth it is again somewhere in Northern Ireland like in late 1968 when The Troubles began at Burntollet Bridge.