about four o'clock
The Duke de Montmorency and the Maréchal Schomberg joined their army about four or five days after , and immediately , according to the cardinal 's instructions , put themselves on the march for the relief of Casale . The army had marched over a great plain , with some marshy grounds on the right and the Po on the left , and as the country was so well discovered that 't was thought impossible any mischief should happen , the generals observed the less caution . At the end of this plain was a long wood and a lane or narrow defile through the middle of it . Through this pass the army was to march , and the van began to file through it about four o'clock . By three hours ' time all the army was got through , or into the pass , and the artillery was just entered when the Duke of Savoy with 4000 horse and 1500 dragoons with every horseman a footman behind him , whether he had swam the Po or passed it above at a bridge , and made a long march after , was not examined , but he came boldly up the plain and charged our rear with a great deal of fury . Our artillery was in the lane , and as it was impossible to turn them about and make way for the army , so the rear was obliged to support themselves and maintain the fight for above an hour and a half . In this time we lost abundance of men , and if it had not been for two accidents all that line had been cut off .