Ginkel found his way blocked by the Jacobite army at Aughrim on the early morning of 12 July 1691. Saint-Ruhe had chosen an extremely strong defensive position, his infantry occupying the slopes of a ridge known as Kilcommadan Hill, with its flanks protected by marshy ground. He left the Jacobite camp "standing with all their baggage [...] not excepting his own"; Parker noted this obliged the Jacobite army to fight and suggested Saint-Ruhe's "resolution to conquer or die". Both armies began a preparatory cannonade at about 2p.m.; Ginkel ordered probing attacks on the Jacobite lines followed by a large-scale infantry assault under Mackay.