French initially viewed the ships as not worthy of concern, though by 1877, public pressure over the new Italian vessels prompted the Navy to order Amiral Duperré. The public outcry also forced the French to design new steel guns to compete with the gigantic Italian guns; the Model 1870 gun was quickly surpassed by the Model 1875, which was installed aboard Amiral Duperré. As the power of guns continued to grow, thicker armor was needed to protect the ships; the full side armor of earlier ironclads could not be thickened without prohibitively increasing displacement. This led to intense discussions in France (and in foreign navies) as to the best way to protect new capital ships; in France, designers considered (de-armoring) their next generation of ironclads. This involved eliminating most of the side armor of the hull and concentrating a sufficient thickness at the waterline only. Guns would be placed in lightly armored barbettes on the upper deck. The French decision was driven by a desire to protect their ships' ability to maneuver, as the unarmored ends of the citadel ships could be easily damaged and flooded. They viewed the ram as a decisive weapon, and a vessel that could no longer maneuver effectively would easily fall victim to a ramming attack. The French differed from their British and Italian counterparts, who decided to shorten the length of their belt armor to save the weight necessary to thicken the remaining portion of armor. Work on the design began with French Naval Minister Charles de Dompierre d'Hornoy's order for the to prepare two options for the new first-class ironclad on 20 October 1873. Work on the project was led by the Director of Material, Victorin Sabattier. One of the options, a combination barbette and central battery ship, was developed further into the . The other, which carried all of its heavy guns in barbettes on the upper deck, went through a series of alterations and Sabattier eventually submitted it to Léon Martin Fourichon, who was then the naval minister, on 8 March 1876. Fourichon approved it on 5 August, and the contract for the vessel was awarded on 4 December. Apart from the main battery arrangement, the ship was in most respects similar to the Dévastations. The ship provided the basis for the very similar design; most of the French ironclads built in the 1880s were developed from these two designs. The