Shortly after giving these verbal orders to Grouchy, which were plainly based on the theory that Blücher had fallen back on Namur, Napoleon received[470] a report from Berton, who commanded the brigade which was sent out in support of Pajol, to the effect that he had been led by the statements of the inhabitants to proceed to Gembloux, where he had seen, at 9 A.M., a Prussian corps of some 20,000 men.[471] This certainly looked as if the Prussians were not retiring on Namur. The first thing to be done, therefore, was to find out where they were going, and what they were proposing to do. At Gembloux, so it now appeared, one would be sure to get on the track of the Prussians, and obtain news of their movements and designs. Accordingly the Emperor, in the temporary absence of Marshal Soult, dictated to General Bertrand the following order[472] to Grouchy:— “Proceed to Gembloux with the cavalry corps of General Pajol, the light cavalry of the 4th Corps, the cavalry corps of General Exelmans, the division of General Teste, of which you will take particular care, it being detached from its own corps,[473] and the 3d and 4th corps of infantry. “You will explore in the directions of Namur and of Maestricht,[474] and you will pursue the enemy. Explore his march, and instruct me respecting his manœuvres, _so that I may be able to penetrate what he is intending to do_.[475] “I am carrying my headquarters to Quatre Bras, where the English still were this morning. Our communication will then be direct by the paved road of Namur. If the enemy has evacuated Namur, write to the general commanding the second military division at Charlemont to cause Namur to be occupied by some battalions of the national guard and some batteries which he will organize at Charlemont. He will give the command to a brigadier-general. “_It is important to penetrate what the enemy is intending to do; whether they are separating themselves from the English, or whether they are intending still to unite, to cover Brussels or[476] Liége, in trying the fate of another battle._[477] In all cases, keep constantly your two corps of infantry united in a league of ground, and occupy every evening a good military position, having several avenues of retreat. Post intermediate detachments of cavalry, so as to communicate with headquarters. Dictated by the Emperor, in the absence of the major-general, to the Grand-marshal Bertrand.”[478] Ligny, 17 June, 1815. Not only is the tone of this letter altogether different from that of the verbal orders previously given, but the duty assigned to Grouchy is a wholly different one.