Boyne, battle of the

Boyne, battle of the, 1690. James II's attempt in the summer of 1689 to reassert his rule over all Ireland faltered on the resistance of Derry and Enniskillen. The Williamite victory at Newtown Butler in July 1689 was the start of the counter-attack. Derry was relieved the following day. In June 1690 William III arrived to take personal command and began his advance south. The Jacobites decided to give battle on the line of the Boyne, north of Dublin. When they met on 1 July, James's army was some 25, 000 strong, William's a little more. In the end, the day was decided largely by a frontal assault across the Boyne. Though casualties were not heavy, the outcome was decisive.