 Complete the following phrase:  Vaillant commanded the fortress at Algiers from 1837 to 1838, recalled to France, he was made director of the École polytechnique. Promoted to lieutet general, Vaillant was put in charge of the building of the Parisian fortifications in 1845 under the command of Dode de la Brunerie. In 1849, Vaillant was given command of the engineers in the French expeditionary corps to Rome. Promoted to Marshal of France in 1851, Vaillant served as Minister of War from 1854 to 1859, holding the position throughout the Crimean War. On the outbreak of the 