Sarsfield, Patrick, earl of Lucan (särsˈfēld, lōˈkən) [key], d. 1693, Irish Jacobite general. A firm supporter of James II, he went with him into exile. He commanded James's forces in Ireland and had some successes, but defeat by William III in the battle of the Boyne (1690) destroyed the Jacobite hopes in Ireland. He was forced (1691) to arrange the disadvantageous treaty of Limerick, surrendering that city. Allowed to go to France, he took thousands of Irish soldiers with him into French service in the War of the Grand Alliance. He fought at Steenkerke (1692) and was mortally wounded at Neerwinden.