It all began on the night of December 3. A fight over a flag in a province officially at peace for years but where street violence has never really ceased.
The spark was the decision to fly the Union Flag above Belfast City Hall on only 20 designated days a year instead of everyday as it had been before. The move infuriated Loyalists.
The Pro-British Unionists and Irish nationalists signed the Good Friday agreement in April 1998 but it took 10 more years to disarm the militias and officially create peace.
Though old rivalries go on and Protestants and Catholics still clash regularly with security forces.
Marches by both sides to commemorate battles and other key historic events have kept tensions high between the communities.
The main paramilitary organisations have long abandoned their campaigns but violent splinter groups still exist and a small number of Republican extremists have carried out several deadly attacks in recent years.
British and Irish politicians are able to maintain a power-sharing coalition government but their efforts are often undermined by violence, of the kinds witnessed in the streets of Belfast recently.
The police suspect pro-British paramilitary organisations of being behind the recent riots.
Belfast’s Protestant community has not only lost the vote on the flag and its majority in the city hall, its population has been in decline for several years and is now almost equal with Catholics.
Often unemployed, some of Northern Ireland’s younger generation feel they have nothing to lose and fall back on old habits, taking to the streets to express their anger even though most people would rather live in peace.