The military operations of the campaign were of course not yet ended, for Moore had not appeared in the valley of the Tagus, marching, as it was believed he would, toward Madrid. The first task was to find him. The different corps were sent out in all directions, but it was not until the middle of the month that the British position was even approximately ascertained. Napoleon was surprised by what he learned, and concluded that the English were about to abandon Portugal in order to secure Ferrol as a base of supplies. His first impulse was to march out himself and prevent such a disaster; on the twentieth half of his army set forth from Madrid, and on the twenty-second he led them through the snows of the Guadarrama. Meanwhile Moore had made his decision. It was to attract the attention of the French, draw them toward him, and then slowly retreat northward, thus leaving Andalusia free from interference, and giving the southern Spaniards time to organize once more and equip themselves for a second Baylen. To this end he prepared on the twenty-third to attack Soult, but, learning of Napoleon's rapid advance, he promptly changed his plan and began his retreat; three days later he led his troops safely across the Esla. Then began a famous chase. The Emperor hurried forward, marching on foot through cold and snow to encourage his tired men. He was eager to strike a blow at his enemy's rear before they should get too far away, and Soult was urged onward to Mansilla, to flank the retreating column. On the twenty-ninth the French cavalry reached the Esla and were driven back by the English rear-guard, while Moore stopped only long enough to destroy the magazines at Benevento, and then hurried on to Astorga. For two days longer the retreat continued. Moore, after many successful skirmishes, reached Corunna, where he hoped to embark. Soult crossed the Esla at last, and on New Year's day, 1809, the Emperor found himself at Astorga. He believed there was an English fleet at Ferrol; the weather was bitter, and his health was jeopardized by the severity of the cold; moreover, disquieting letters arrived, and he determined that this game was not worth the candle. Soult was intrusted with the pursuit, Ney was stationed at Astorga as a reserve, and Napoleon, putting himself at the head of his guards, set out for Valladolid, which he reached on the sixth. After a rest of ten days, new and more disquieting despatches made clear the urgent need for his presence in Paris, though his task in Spain was far from ended. On January twenty-third he reached the Tuileries.