Bosquet was amongst the earliest chosen to serve in the Crimean War, and at the Battle of Alma his division led the French attack. When the Anglo-French troops formed the siege of Sevastopol, Bosquet's corps of two divisions protected them against interruption. Referring to the Charge of the Light Brigade, Bosquet muttered the memorable line: "C’est magnifique, mais ce n’est pas la guerre: c'est de la folie" ("It is magnificent, but it is not war: it is madness"). His timely intervention at the Battle of Inkerman (5 November 1854) secured the victory for the allies. During 1855 Bosquet's corps occupied the right wing of the besieging armies opposite the Mamelon and Malakov. He himself led his corps at the storming of the Mamelon (7 June), and at the grand assault of 8 September he was in command of the whole of the storming troops. In the struggle for the Malakov he received another serious wound.