The day on which Orangemen in Northern Ireland and elsewhere celebrate the anniversary of William of Orange's victory at the Battle of the Boyne. The focal point of the province's Marching Season, the occasion is marked by parades by members of the Orange Order, generally accompanied by marching bands and other supporters. It is a public holiday in Northern Ireland, and generally looked on by the Unionist population as a great day out. Nationalists however, are not too sure, as the whole thing smacks of protestant triumphalism over catholics. A number of the parades are contentious, because they are routed through predominantly catholic areas, and the Orangemen refuse to negotiate their right to march with the residents. This has led to the institution of a Parades Commission to decide on the routing of contentious parades. This commission is none too popular with Orangemen.