six o'clock
His heavy columns fared exactly as the French columns had fared when they assaulted the English . But it was not within the power of ten thousand men to hold off thirty thousand forever , and there were soon that number of Prussians at the point of contact . Frantic messages from Lobau caused the Emperor to send one of the divisions of the Old Guard , the last reserve , to his support . It was now after six o'clock , the declining sun was already low on the horizon , the long June day was drawing to a close . The main force of the Prussians had not yet come up to the hill and ridge of Mont St. Jean . Wellington , in great anxiety , was clinging desperately to the ridge with his shattered lines wondering how long he could hold them , whether he could sustain another of those awful attacks . His reserves , except two divisions of light cavalry , Vivian 's and Vandeleur 's , and Maitland 's and Adams ' brigades headed by Colborne 's famous Fifty-second Foot , among his troops the de luxe veterans of the Peninsula , had all been expended .