The Battle of Curlew Pass was a pivotal engagement during the Nine Years’ War, fought between the forces of Hugh Roe O'Donnell and Sir Conyers Clifford. As a strategic move, O'Donnell sought to intercept an English contingent aiming to assist Collooney Castle, which was under siege. The English troops, unaware of the imminent danger, marched through the rugged terrain of Curlew Pass, a decision that would lead to their ambush. Utilizing knowledge of the local topography, O'Donnell positioned his forces advantageously to strike with speed and precision. The attack was executed on August 15, catching Clifford's men off guard. The engagement unfolded quickly, with O'Donnell's forces employing guerilla tactics that disrupted the rank-and-file English soldiers. Despite their attempts to regroup, the English were unable to withstand the barrage. Reports from the action indicate that the Irish inflicted heavy casualties, including the death of Clifford himself. The precise numbers of the dead on both sides remain uncertain; however, the psychological impact of the conflict likely had far-reaching consequences. O'Donnell’s triumph at Curlew Pass exemplified his military acumen and the capability of Irish forces to challenge English control effectively.In the broader context of the Nine Years' War, this victory contributed to a growing sense of confidence among the Gaelic lords in Ireland. It underscored the critical role of local knowledge in warfare and reinforced the notion that with careful planning and familiarity with the terrain, smaller forces could achieve significant victories against larger armies. The aftermath of the battle left a mark on English strategic thinking in Ireland, compelling them to rethink their military approaches and reinforcing the resolve of the Irish opposition.