army, under Moore, had advanced to Salamanca and were joined by Hope's detachment on 3 December when Moore received news that the Spanish forces had suffered several defeats. He considered that to avoid disaster he must give up and retreat back to Portugal. Moore, before retreating, received intelligence of Soult's 16,000-man corps' scattered and isolated position at Carrión and that the French were unaware of the British army's position. On 15 December, he seized this opportunity to advance on the French near Madrid, hoping that to defeat Soult and possibly divert Napoleon's forces. A junction with Baird on 20 December, advancing from Corunna, raised Moore's strength to 23,500 infantry, 2,400 cavalry and 60 guns and he opened his attack with a successful raid by Lieutenant-General Paget's cavalry on the French picquets at Sahagún on 21 December. However, Moore failed to follow up against a surprised Soult. Moore halted for two days and allowed Soult to concentrate his corps. Prelude Retreat to Corunna Once Moore made his presence known Napoleon responded with customary swiftness and decisiveness. The Spanish were defeated and no longer an organized threat. His army was generally concentrated while the enemy was dispersed. With the initiative firmly in his grasp, Napoleon seized the chance to destroy Britain's only field army. When Moore realized he was in serious danger of being trapped he called off his advance and went into headlong retreat. This epic dash and chase would cover more than , during which the British cavalry and the infantry of the Light Brigade were used to cover the movements of Moore's army after their retreat began on 25 December. This saw them engage the French in small rearguard clashes, including defeating a French cavalry force and capturing General Charles Lefebvre-Desnouettes at Benavente before entering the mountains of Galicia, and another at Cacabelos where General Colbert-Chabanais was killed by a British rifleman. The retreat of the British, closely followed by their French pursuers, took them through mountainous terrain in dreadful conditions of cold and snow and was marked by exhausting marches, privation, and suffering. Moore was joined at Astorga by General Romana leading the remnants of Blake's Spanish forces and Romana proposed they make a stand. However, with Napoleon closing in, Moore declined and continued his retreat north while Romana went west towards Portugal. On the march between Astorga and Betanzos the British army lost 3,000 men with 500