After the French were driven out of Spain, Merlin received promotion to general of division in the French army on 5 January 1814. After being placed in charge of the central cavalry depot on 21 January and in command of some National Guard units on 31 January, he assumed command of a cavalry division on 11 February. At about this time, Emperor Napoleon reorganized his cavalry, forming the I Cavalry Corps from the divisions of Merlin and Étienne Tardif de Pommeroux de Bordesoulle with Bordesoulle in command of the corps. Merlin's 1st Light Cavalry Division first appeared in the order of battle during the Battle of Champaubert on 9 February. At the Battle of Vauchamps on 14 February, the 1st Brigade under François Isidore Wathiez consisted of the 6th, 7th and 8th Hussars and the 1st, 3rd, 5th, 7th and 8th Chevau-léger Lancers. The 2nd Brigade under Claude Raymond Guyon was made up of the 1st, 2nd, 3rd, 6th, 8th, 9th, 16th and 25th Chasseurs à Cheval. On 20 February, Wathiez's brigade counted 1,063 sabers while Guyon's brigade had 956. The regiments were small; the largest numbered 177 and the smallest 84 horsemen.