Today 319 ago the hard fought battle of Aughrim was fought on 12 July 1691 (O.S.). The outcome of this battle was more decisive than that of the much more celebrated Battle of the Boyne fought a year earlier. Though the Williamite Army certainly had the better cards in 1691, there was a real chance that the war in Ireland could, literally, be dragged on well into 1692. This would certainly have had consequences for the operations in the main theater of war, the Spanish Netherlands.
The Williamite Army (composed of Dutch, Danish, Ulster and English regiments) was commanded by the future Earl of Athlone. The Irish were led by the French general Charles Chalmont, marquis de Saint-Ruth. Saint-Ruth would be killed during the battle.
After the battle, and defeat and rout of the Irish army, the city of Galway surrendered without offering resistance ten days later. The 2nd Siege of Limerick followed in August. Here the Jacobite high-brass thought is was better to negotiate profitable terms of surrender, and continue the fight for the Jacobite cause elsewhere. This led to the Treaty of Limerick of September 3rd 1691, and end of the Williamite War in Ireland. Large part of the Irish Army went into exile to France, forming a Jacobite Army in exile for James II. The bulk of the Williamite regiments were almost immediately transferred to the Spanish Netherlands.
An order of battle of the Williamite Army was posted earlier on this blog. Information on the Irish/Jacobite order of battle is not forthcoming unfortunately. Hayes-McCoy discusses the Jacobite army in his paper The Battle of Aughrim 1691 (in: Journal of the Galway Archaeological and Historical Society, Vol. 20, No.1/2 (1942), pp. 1-30), and, more recently, Richard Doherty discussed the battle in The Battle of Aughrim (in: History Ireland, Vol. 3, No. 3 (1995), pp. 35.42).