 Complete the following phrase:  On 28 November Napoleon, engaged in pressing the retreat of Sir John Moore towards Corunna, rode ahead of his army into the village of Valderas, which the British had quit but two hours previously. He was accompanied only by his staff and a squadron of the chasseurs. When Marshal Ney found that the Emperor had thus exposed himself he said to him: Sire, I thank Your Majesty for acting as my advance guard. That it had been imprudent was proved next day 29 December when General Lefebvre-Desnouettes caught up with the British rearguard, forded the River Esla and drove in their pickets, only to be rudely counter-attacked by Lord Paget the Uxbridge of 