A province echoing to the sound of marching feet

About 4,000 parades are held every year during Northern Ireland's marching season.

The three main Protestant orders to hold parades are the Orange Order, the Apprentice Boys and the Royal Black Preceptory.

Many parades are non-controversial, but a minority, particularly those that pass through Catholic areas, can lead to sectarian violence.

Key dates are 6 July, when the Orange Order marches through Drumcree (see map) and 12 July, when marches are held in 19 venues to commemorate the Battle of the Boyne. On 9 August the Apprentice Boys will parade through Londonderry to commemorate the end of the siege of the city in 1690; on 13 December they mark the beginning of the siege. On 10 August, nationalists remember the anniversary of the introduction of internment without trial in1971.

Drumcree last year cost pounds 30m to police.