His preparations for this march were all made, when, on the afternoon of the 5th, he learnt, more accurately than he had before done, the true situation of the royal army, and from the information now received, he thought it expedient to consult his principal officers, whether it might not be advisable to attempt to surprise the enemy by a night attack upon their quarters.  The prevailing opinion was, that if the infantry were not entrenched the plan was worth the trial; otherwise not.  Scouts were despatched to ascertain this point, and their report being that there was no entrenchment, an attack was resolved on.  In pursuance of this resolution, at about eleven at night, the whole army was in march, Lord Grey commanding the horse, and Colonel Wade the vanguard of the foot.  The duke’s orders were, that the horse should first advance, and pushing into the enemy’s camp, endeavour to prevent their infantry from coming together; that the cannon should follow the horse, and the foot the cannon, and draw all up in one line, and so finish what the cavalry should have begun, before the king’s horse and artillery could be got in order.  But it was now discovered that though there were no entrenchments, there was a ditch which served as a drain to the great moor adjacent, of which no mention had been made by the scouts.  To this ditch the horse under Lord Grey advanced, and no farther; and whether immediately, as according to some accounts, or after having been considerably harassed by the enemy in their attempts to find a place to pass, according to others, quitted the field.  The cavalry being gone, and the principle upon which the attack had been undertaken being that of a surprise, the duke judged it necessary that the infantry should advance as speedily as possible.  Wade, therefore, when he came within forty paces of the ditch, was obliged to halt to put his battalion into that order, which the extreme rapidity of the march had for the time disconcerted.  His plan was to pass the ditch, reserving his fire; but while he was arranging his men for that purpose, another battalion, newly come up, began to fire, though at a considerable distance; a bad example, which it was impossible to prevent the vanguard from following, and it was now no longer in the power of their commander to persuade them to advance.  The king’s forces, as well horse and artillery as foot, had now full time to assemble.  The duke had no longer cavalry in the field, and though his artillery, which consisted only of three or four iron guns, was well served under the directions of a Dutch gunner, it was by no means equal to that of the royal army, which, as soon as it was light, began to do great execution.  In these circumstances the unfortunate Monmouth, fearful of being encompassed and made prisoner by the king’s cavalry, who were approaching upon his flank, and urged, as it is reported, to flight by the same person who had stimulated him to his fatal enterprise, quitted the field accompanied by Lord Grey and some others.  The left wing, under the command of Colonel Holmes and Matthews, next gave way; and Wade’s men, after having continued for an hour and a half a distant and ineffectual fire, seeing their left discomfited, began a retreat, which soon afterwards became a complete rout.