On 20 December the French forces arrived again at Zaragoza. Moncey split his forces: One division under
General Gazan was assigned to the north, Mortier's corps was posted to the west, and Moncey's corps went to the south.
Phase 1: The outworks 20 December 1808 – 15 January 1809 The first key objective was the weak Spanish
outworks on Monte Torrero. On 21 December 1808, three batteries began bombarding these positions followed by an attack by twenty battalions of infantry which successfully drove the Spanish out of these positions. This initial success was to prove decisive as once again the French were able to deploy their main gun batteries on Monte Torrero and were ultimately successful in breaching the southern wall. Gazan launched an attack on the same day against San Lazaro, however, this attack was unsuccessful due to the strength of the Spanish defence. On 22 December 1808 Moncey formally demanded the surrender of the city but this was refused. Moncey then decided to concentrate his efforts on the southern side of the city and prepared attacks against the Pillar redoubt and against the San Jose convent. Preparations were also made for an attack opposite the castle of
Aljafería in the north-west. On 29 December 1808 Moncey was reassigned to Madrid and was replaced in command of the 3rd corps by General
Jean-Andoche Junot. Mortier was then the senior officer however he worked in partnership with Junot until he was himself reassigned on 2 January 1809. The French preparations were finally complete on 10 January 1809 and they commenced bombarding the Pillar Redoubt and San Jose. By the end of the day, the San Jose walls were about to collapse. Palafox counter-attacked the French guns at 1 am on 11 January 1808 but this attack failed and the Spanish troops withdrew into the city. The French attack on the Pillar Redoubt continued until the night of 15–16 January 1808 when the
1st Polish Vistula Regiment stormed the position. The Spanish had already left destroying the bridge across the Huerva river at the same time.
Phase 2: Attacking the walls, 16–27 January 1809 On 16 January 1809 the main Spanish outworks were in French hands. The French armies could now concentrate on breaching the walls of Zaragoza. From 17 January 1809 the French began a bombardment of the walls from the San Jose redoubt. Palafox knew the walls would not last long and prepared barricades in the city, turning it into a maze of small forts. In January Junot was replaced with
Marshall Lannes who had been recovering from an earlier injury. Sickness was now creating problems on both sides. On the French side there were now only 20,000 fit infantry. At the same time new Spanish forces were being created near the city under Francisco Palafox (younger brother of the General) and the Marquis of Lazan (older brother of the General). Lannes was concerned about his rear and recalled Mortier's division which had been protecting the lines of communication between Madrid and Zaragoza. On 26 January Mortier's army defeated a peasant militia of some 4–5 thousands men at
Alcañiz. The French attack commenced on 24 January 1809 when three beachheads were captured across the Huerva river. The main assault began on 27 January 1809 through three breaches in the city walls. Lannes broke through two breaches and captured the battery at the south-eastern corner and also the convent of Santa Engracia in the south-west. This marked the end of this phase of the siege with the final phase of vicious street fighting to follow.
Phase 3: Street fighting 28 January – 20 February 1809 The Spanish defenders had been preparing for street fighting from the beginning. Lannes, however, had decided on a slow block-by-block siege of each individual fortification in order to minimise French casualties. Individual battles were remarkable for their ferocity. At one point in the San Augustin Convent, the French held the altar end of the chapel and exchanged shots for hours on end with the Spanish entrenched in the nave and the belfry. However, French superiority in equipment and training took its toll, and thousands were falling daily both in the fighting and to disease, which was rampant throughout the city. By February illness was decimating the population of Zaragoza and only 8,495 men remained of the original garrison of 32,000 men. There were 10,000 dead and 13,737 sick or wounded. The French were unaware of this however and morale was low due to the apparent never-ending battle in the narrow streets. Disappointed with the slow progress, Lannes ordered the troops north of the river to make a second attack on San Lazaro and on 18 February 1809 this attack was successful. The northern part of Zaragoza could now be attacked with artillery. By 19 February 1809 the Spanish defence was failing and Palafox himself was seriously ill. He sent his aide to Lannes to discuss terms of surrender. He then resigned his military command in favour of General St. March, and his civil command of the city to a 33-member council of local citizens. The first offer of surrender was rejected and fighting resumed on 20 February 1809 but the civilian council quickly negotiated to end the fighting which ceased that evening. Most of the city lay in ruins, and around 54,000 people had perished in the siege. ==Aftermath==