18 April 1690: Over 5,000 Irish soldiers organised in five Regiments sailed from Ireland for France at the request of Louis XIV [above]. He sent some 6,000 French regulars in exchange for these men. The Irish troops formed the nucleus of the famous ‘Irish Brigade’ that was to continue in French service for over 100 years until just after the Revolution.

The King of France wanted to support James II in his expedition to retake the British crown from the Dutchman William of Orange. However he could not afford the loss of 6,000 of his own soldiers during his own War against Holland. So Louis requested Irish replacements to take their place. The Irish regiments sailed out on the same ships that landed the French troops under Count de Lauzun.

After arriving in France, the five regiments were reorganized into three, commanded respectively by Justin McCarthy (Lord Mountcashel), Daniel O'Brien, and Arthur Dillon. Mountcashel was in overall command this Irish Brigade in the service of France. He had grown up in France, and became fluent in the French language. His father had lost everything due to his participation in the fight against Cromwell and subsequently went into exile in France. After the Treaty of Limerick Patrick Sarsfield’s men joined Mountcashel’s brigade in late 1691.

Like Sarsfield, Mountcashel did not survive for very long in French service. Shortly after his arrival in France he was seriously wounded in the chest fighting in down south in Savoy. Although he recovered from this wound and continued to command the Irish Brigade, it continued to dog him. He eventually had to retire from French Service and much weakened in health he died in 1694.