Le cuirassé d'escadre Carnot est issu du programme naval de 1890 dit “flotte d'échantillons" – dont faisaient partie également Charles Martel, Jauréguiberry, Masséna et Bouvet – que la presse n'a pas tardée à qualifier de "flotte de mastodontes". Il s'agissait de tester différents composants sur plusieurs bateaux afin d'obtenir un futur cuirassé idéal. Ce fut loin d'être un succès.
Mis en chantier en 1891 sous le nom de Lazare Carnot, il sera armé définitivement en juin 1897 toujours sous le nom de Carnot, mais pas Lazare, Sadi, président assassiné en 1894. Après une vie sans histoire, alternativement à l'escadre de Méditerranée et celle du Nord, il est mis en réserve en 1913. Le 1er avril 1914, il sert de ponton-caserne à Brest. Seule son artillerie principale, débarquée, participera à la guerre et sera saisie par les Allemands. Carnot est rayé en 1919.
The French Battleship Carnot was named after the popular president of France, Marie François Sadi Carnot, who was assassinated in 1894 in Lyon by an Italian anarchist. This ship was the last battleship built in Toulon, part of a development series of ships of a broadly similar theme ; each one being( supposedly) an improvement; the other ships being Charles Martel, Jaureguiberry, Masséna and Bouvet. Laid down in July 1891, she was launched 12th July 1894. Drawn out construction times in this era were the norm… however Carnot holds the record for the longest!!
After extensive trials, repairs and modifications, Carnot is finally declared operational and fully fitted on 25 June 1897 and deployed with the Eastern Mediterranean and Levant squadron. She remained in the Mediterranean until January 1900 when moved to Brest along with Massena as part of the Northern squadron. She returned to the Mediterranean for summer manoeuvres in June. She spent almost two years from late 1900 – 1902 in the dockyard undergoing repairs and improvements to parts of the underwater structure and was thereafter assigned along with Brennus to the reserve squadron. In August 1905 almost the entire Northern Squadron represented France at the Great International Fleet review of 1905 at Spithead in the Solent in England. October of the same year saw Carnot return to the drydock with further extensive bilge keel problems.
In January 1906 Carnot along with Massena, Jaureguiberry returned again to the Mediterranean. 1907 through to 1913 saw the ship in and out of the dockyards for continuing repairs and brief periods of commission in both the Mediterranean and the Northern fleets as well as being held in reserve fleets. Unfortunately by this time Carnot was out of date and was decommissioned on 1 April 1914 to be used as floating barracks. At the end of July 1919 she was abandoned and sold for scrapping, being finally broken up in 1922.