On the 1st of July the Enniskilleners were to play a very important part in that famous battle. The centre of William's army on that day was composed of four regiments of foot the Dutch Blue Guards, the Brandenburghers, the Huguenot Regiment and the Enniskilleners. William knew that the brunt of the fighting would be borne by these regiments and that they would not falter in their resolve. The first two because of their love for him and his cause, the latter two because of their devotion to the Reformed Faith.
When William knew that his horse regiments had successfully forded the Boyne upstream, he sent orders to his centre division to cross the river. The four regiments stepped forward to the tune of 'Lilliburlero', which had chased James from England and was now heralding his defeat at the Boyne. The centre regiments gave a good account of themselves and although repeatedly attacked by the Irish horse, held firm their positions. When ordered to advance again they did so in good order, but the Irish rallied and stopped the advance at this point in the battle.
Hamilton's frish Horse attacked and the critical moment in the conflict had arrived. William rode up to the Ermiskilleners, and asked them what they would do for him. Tradition alleges that David McKinley, an Enniskillen trooper, who had pointed out the ford to the King when he and his division were about to cross the river, cried out, "Anything your Majesty pleases".