The combat of Alcañiz was a minor French victory during the second siege of Saragossa. On 22 January Marshal Lannes had been placed in charge of the French forces conducting the siege. His first concern was to protect his rear – it was clear that a period of street fighting was about to begin, which would leave Lannes’ men very vulnerable to any attack by Spanish relief forces, and there were not enough troops around Saragossa to provide a covering force as well as to attack the city.
One force that was available was Suchet’s division under the command of Marshal Mortier, which had been withdrawn from the siege by Napoleon at the start of January to protect the French lines of communication back to Madrid. Lannes decided to recall this division to Saragossa and use it to protect his back during the assault.
Mortier was soon in place south of Saragossa. His main concern was the increasingly large number of insurgents that were appearing in the Lower Ebro. Accordingly he dispatched two battalions of infantry and two regiments of cavalry, under the command of General Wathier, into the Lower Ebro. On 26 January this force ran into a band of 5,000-6,000 peasant militia supported by one new regiment of Aragonese volunteers outside the town of Alcañiz. The inexperienced Spanish troops attempted to defend the town, but Wathier’s men soon drove them away.
The main result of this minor victory was the capture of a supply depot contained 20,000 sheep and 1,500 sacks of flour, which had been gathered at Alcañiz in preparation to be rushed into Saragossa if the siege should be lifted.