About Neil O'Neill
Sir Neil O'Neill commanded a regiment of Jacobite dragoons (mounted infantry) at the Battle of the Boyne. http://en.wikipedia.org/wiki/Battle_of_the_Boyne
At dawn on 1 July 1690, a force of 10,000 men, led by Count Meinhard Schomberg and General James Douglas, left the Williamite camp near Tullyallen and marched upstream to attack the Jacobite left wing. Slane bridge had been broken down by Jacobite troops, and the Williamites forded the river at a point between Rossnaree and Slane which "led to a very fine plain"
A charge by a regiment of Jacobite dragoons (mounted infantry) held up their advance for half-an-hour, until the Jacobite commander, Sir Neil O'Neill, was mortally wounded.