French fire, particularly heavy mortars mounted on bomb vessels and Paixhans guns on frigates, silenced the citadel and forced it to surrender on 28 November, a remarkable feat for the time.

The swift capture of the citadel by a small squadron of relatively light warships stunned military observers who had gathered to watch the scene, and marked the beginning of the era of shell artillery and the modernization of navies around the world.

Civilian populations suffered from these struggles for power, as well as foreign expatriates, as the country had attracted considerable investments, notably in the mining industry.

[1] The French government made several attempts at settling the matter by commercial agreements, demands for compensations and even threats of armed interventions, but to no avail.

As Mexico did not possess any warship capable of challenging the squadron, the frigates blockaded the city unopposed, seizing 36 merchantmen in the process,[2] but President Anastasio Bustamante refused to satisfy the demands.

However, the fortress of San Juan de Ulua was much too strong for Bazoche's forces, who were further exhausted by months of campaigning and suffered from yellow fever.

Furthermore, the squadron had two steamers, Météore and Phaéton, to facilitate maneuvers in the harbor, and two corvettes armed en flûte, Fortune and Caravane, for logistics.

With the nearest French stations in Martinique and Guadeloupe, at the other end of the Gulf of Mexico, the squadron had to use Havana as a base, and thus made itself dependent on the good will of Spanish authorities.

A storm partially scattered the fleet en route, whose main forces reached Veracruz on 29 October, to be rejoined by later ships around mid-November.

The French blockade did hinder the Mexican economy, but it did not have a crucial impact, as the country was largely self-sufficient and other needed goods could be imported from Corpus Christi harbor, in Texas, and across the Rio Bravo.

The French, on the other hand, were taking the opportunity to reconnoiter the coast, measure the depth of water and observe the Mexican forces; they had noticed that the artillery of the fort was in a state of disrepair and a naval bombardment could be carried out.

At some point cannon fire from the fort penetrated the prince's cabin and shattered his dish; Joinville then took off his hat and saluted the Mexicans.

Baudin accepted that 1000 Mexican soldiers stay in Vera Cruz, as the French did not have sufficient troops to formally occupy the city.

The capture of San Juan de Ulua came as a surprise to the Mexican government, which declared war on France, expelled all French citizens established in Mexico, relieved Rincón of command and sent an army of 3200 men, under Santa Anna and Arista, to retake Veracruz.

On 5 December, at 5:00 in the morning, boats from the squadron landed 1500 men on the beaches before Veracruz; they split into three columns: two wings ascended the city walls near the strongholds of Santiago and Conception.

The central column, under François de Joinville, was tasked with blowing up the door commanding access to the harbor, storm the city and attack the buildings where the Mexican generals were thought to be staying.

The double defeat in San Juan de Ulua and Veracruz itself induced the Mexican government to reopen negotiations to settle the conflict, especially since the French had not increased their demands as their position grew stronger.

The British offered their mediation to ease the process, dispatching their Northern American squadron in the Gulf of Mexico,[4] along with Ambassador Richard Pakenham with a fleet.

Neutral observers, notably from HMS Satellite, under Captain Robb, and USS Levant, reported the effect of the French bombardment.

Santa Anna, who previously had been discredited by the Texas Revolution, was hailed as a hero for his ultimately failed attempt at a counterattack; severely wounded, he had a leg amputated on 6 December and battled death for days.

In France the expedition elevated two officers to prominence: Baudin, an elderly veteran of the Napoleonic era; and the 20-year-old Prince of Joinville, third son of the ruling Louis-Philippe, who had commanded the Créole during the bombardment and the main column during the raid.