The Napoléon class was a late type of 90-gun ships of the line of the French Navy, and the first type of ship of the line designed from the start to incorporate a steam engine. Designed by Henri Dupuy de Lôme, the prototype Napoléon displayed such outstanding performances during her trials that a production series was immediately ordered, yielding the Algésiras sub-class. Furthermore, construction of the two Bretagne class 130-gun ships was interrupted: Desaix, whose construction had only just started, was cancelled altogether and replaced with Arcole, while Bretagne was dismantled and entirely rebuilt on principles heralded by Napoléon. Further improvements to the Algésiras type yielded the Ville de Nantes sub-class.