T he rebellion was launched by the Society of United Irishmen, founded in Belfast in 1791. The founders were Protestant liberals seeking parliamentary reform, inspired by Theobald Wolfe Tone’s call for Catholic emancipation. Encouraged by the revolutions in France and America, they rapidly grew and developed into a revolutionary republican organisation. When France declared war on Britain in 1793, they were brutally suppressed. Their policy was to wait for French aid, but the destruction of the organisation by suppression forced an early rising in 1798. When the French did arrive, they were too few, too late.
By 1798 there were 280,000 sworn members of the United Irishmen. They were divided by sectarian distrust and political differences. The Protestants, mainly middle class Presbyterians, were struggling for an end to restrictions on Irish trade and for religious equality, while the rural Roman Catholics, were organising for agrarian reform and catholic emancipation.
In 1778/9, France and Spain joined the American War of Independence against Britain. With the regular army abroad, patriotic Irish Protestants formed the Volunteers, to defend against invasion.
There was much support in Ireland for the Americans, many of whom were Protestant dissenters from Ulster. The Volunteers began to press for reform and greater independence. To stabilise Ireland, the British government pressed the Dublin parliament to give Catholics the vote in 1793. At the same time, the Volunteers were suppressed and replaced by a home defence force of paid militias.
The well-armed but poorly trained militias formed the bulk of the Crown forces. Many defected to the rebels, along with former Volunteers. Most of the rebels lacked both training and equipment – the standard weapon was a pike, made by the local blacksmith. Most of the combatants on both sides were Irish, brother fighting brother. The campaigns were fought with a cruelty so often seen in civil wars.
The rebel leadership looked to France for support, but the timing was never right. A French force of over 14,000 men set out in 45 ships in 1796, but was scattered by winter storms in Bantry Bay. This triggered a vicious suppression in Ireland, forcing the United Irishmen to rise, without French support, in the spring of 1798.
When Humbert arrived in Killala with 1,100 men in late August, the rebellion was virtually over in the rest of the country. He was to have been followed immediately by much larger forces, but these did not set out until October.
In Ulster, the largely Protestant rebels under Henry Joy McCracken had been defeated at Antrim on June 6th, Munroe’s forces at Ballinahinch a week later. At the seat of rebellion in Wexford, defeat at New Ross and Arklow had been followed by annihilation at Enniscorthy, at the hands of General Lake, on 21st. June.