Napoleon III

The declaration was on the 27th

France's entry into the war is usually filed under 28 March 1854. French legal scholarship places Napoleon III's declaration on 27 March, made under the French emperor's constitutional authority to declare war.

A message delivered in his name to the Senate and Corps législatif announced that Russia's latest decisions had placed it in a state of war with France, and assigned responsibility for that to the Russian government. Contemporary reporting says the Corps législatif received the announcement with acclamations and assurances of unanimous support.

The 28th is securely associated with Britain's published declaration, which probably produced the conflation.

Silence as the trigger

The declaration followed Russia's refusal to answer the Anglo-French ultimatum demanding withdrawal from the Ottoman principalities of Moldavia and Wallachia. Six days were allowed for a reply; the demand was for complete evacuation by 30 April 1854.

France thereby became a belligerent alongside the Ottoman Empire, which had been at war with Russia since October 1853. Britain issued its own formal declaration the following day.

The article filed under this date is about a battle

The existing corpus article for this slug describes the allied landing in Crimea and the Battle of the Alma — fought on 20 September 1854, nearly six months after the declaration and hundreds of miles away.

It never identifies Napoleon III, the message to the legislative chambers, Russia's refusal to answer the ultimatum, or the legal change that made France a belligerent. Its force and casualty figures, whatever their value for Alma, cannot substantiate a declaration of war made in Paris.