Daniel O'Brien, Viscount Clare
O'Brien, Daniel, Viscount Clare, (brother of the 4th Earl of Thomond), was created Viscount Clare in 1662 for his signal services in the wars of Ireland, Daniel, his grandson, the 3rd Viscount, espoused the cause of James II., raised two regiments of foot and one of dragoons for his service, fought at the Boyne, and retired to France. His regiments ultimately formed part of the Irish Brigade (in which his dragoons specially distinguished themselves), and his estates, comprising about 60,000 acres in Clare, were forfeited. Viscount Clare's dragoons fought at Ramillies and elsewhere on the Continent, and retrieved the dishonour of their unsteadiness at the Boyne. His sons both fell in battle — Daniel, the 4th Viscount, at Pignerol in 1693, and Charles, the 5th Viscount, at Ramillies in 1706. This branch of the O'Briens became extinct on the death of Charles, the 7th Viscount, at Paris in 1774.
Sources
263. O'Briens, Historical Memoir of the: John O'Donoghue. Dublin, 1860.