It was a fairly innocuous event that triggered the period of sectarian violence known as the Armagh Disturbances of the late-eighteenth century. At Mountnorris Fair on the 14th of July, 1784, two Presbyterians under the influence of alcohol fought, the victor being supported by a Catholic. The defeated Protestant and his friends formed a compact to exact revenge on the Catholic man and any who would aid him, whatever their religion. This group became known as the Knappagh Fleet (after the townland of Edenknappagh where they were based) and they raided into the local townlands and parishes. The formation of counter 'fleets' led to 'tit-for-tat' violence in the area, as the violence took on a sectarian aspect.
Spreading to Hamiltonsbawn, Killeen and Redrock, the violence was fuelled by the use of illegal poteen. Gradually, the Protestant groupings became allied to the Peep' o' Day Boys, while the Catholic associations formed into units of Defenders. At one stage, the Curate of Mullabrack Church of Ireland, the Reverend Courtney, was very badly beaten and the Primate of Armagh became a target in the continued violence.
Modern explanations for the violence point to the increased competition between Catholic and Protestant tenants for increasingly subdivided land, and to Protestant economic concerns at the increasing number of Catholics working in the weaving industry. Fears that Catholics might acquire substantial arms were aggravated by attempts of liberal magistrates (such as Mr. Blackhall of the Cope Estate at Mountnorris) to enrol young Catholic men in the declining, volunteer corps.