King Henry, however, did not give indulgence to inactivity; but, muttering that his armies had been a laughing-stock to William, immediately collected all his forces, and, dividing them into two bodies, he over-ran the whole of Normandy. He himself headed all the military power which came from that part of Celtic Gaul which lies between the rivers Garonne and Seine; and gave his brother Odo the command over such as came from that part of Belgic Gaul which is situated between the Rhine and the Seine. In like manner William divided his army, with all the skill he possessed; approaching by degrees the camp of the king, which was pitched in the country of Briony, in such a manner, as neither to come to close engagement, nor yet suffer the province to be devastated in his presence. His generals were Robert, earl of Aux; Hugo de Gournay, Hugo de Montfort, and William Crispin, who opposed Odo at a town called Mortemar. Nor did he, relying on the numerous army which he commanded, at all delay coming to action; yet making only slight resistance at the beginning, and afterwards being unable to withstand the attack of the Normans, he retreated, and was himself the first to fly. And here, while Guy, earl of Ponthieu, was anxiously endeavouring to revenge his brother, he was made captive, and felt, together with many others surpassing in affluence and rank, the weight of that hand which was so fatal to his family. When William was informed of this success by messengers, he took care that it should be proclaimed in the dead of night, near the king’s tent. On hearing which he retired, after some days spent in Normandy, into France; and, soon after, ambassadors passing between them, it was concluded, by treaty, that the king’s partizans should be set at liberty, and that the earl should become legally possessed of all that had been, or should hereafter be, taken from Martel.