Boyne, battle of

Boyne, battle of (1 July 1690), in the Williamite War. The Jacobites chose the river Boyne as the best barrier against William III's progress south towards Dublin, garrisoning Drogheda and placing their main force (25,000 men) at the most likely crossing point, Oldbridge, 3 miles upstream. The Williamite army, 36,000 strong, camped opposite, on the north bank. However, Schomberg's son Meinhard led a third of the Williamite force upriver, where they crossed the Boyne at Rosnaree after a half‐hour engagement against 800 dragoons commanded by Sir Neil O'Neill. James II, overestimating the threat, led two‐thirds of his army to the left, but was unable to attack because of two intervening ditches. Meanwhile the main Williamite army crossed at Oldbridge, overwhelming the depleted Jacobite right, though the cavalry under Tyrconnell made repeated counter‐attacks. Threatened with encirclement, the main Jacobite force retreated. Since it had never engaged the enemy, overall losses were relatively light, about 1,000 Jacobites and 500 Williamites being killed.

Less strategically important than Aughrim, the battle owed its subsequent fame primarily to the presence in person of both William, who remained in the centre of the fighting throughout, and James, whose precipitate flight from the battlefield aroused derision on both sides. Overshadowed for most of the 18th century by celebrations of King William's birthday (4 Nov.), its anniversary became the central festival of the Orange society from the 1790s. The Order's decision to celebrate the main anniversary on 12 July seems to have derived from a misunderstanding of the 1752 calendar reform. The battle was in fact fought on 11 July new style.