Continuous tinkering with the Marceau design during their long construction produced badly flawed vessels that were superseded by more powerful pre-dreadnought battleships almost immediately after the French commissioned them in the early 1890s.

All three Marceaus were modernized in the early 1900s, receiving new water-tube boilers and having their top-heavy superstructures and masts cut down, but they saw little activity afterward.

By that time, the Italian Regia Marina (Royal Navy) had begun its own expansion program under the direction of Benedetto Brin, which included the construction of several very large ironclad warships of the Duilio and Italia classes, armed with 450 mm (17.7 in) 100-ton guns.

The French initially viewed the ships as not worthy of concern, though by 1877, public pressure over the new Italian vessels prompted the Navy's Conseil des Travaux (Board of Construction) to design a response, beginning with the barbette ship Amiral Duperré and following with six vessels carrying 100-ton guns of French design.

The Amiral Baudins were too advanced in their construction to allow their design to be revised, but the other four vessels of the program, which became Hoche and the three Marceau-class ironclads, had not yet begun building.

Their design, which was prepared by the naval engineer Charles Ernest Huin, was radically altered from the Amiral Baudin arrangement to what would become the standard for future French capital ships for the next two decades.

The large caliber guns were increased to four, one forward, one aft, and a wing mount on either side amidships to maximize end-on fire (which was emphasized by those who favored ramming attacks).

The shipyard engineers proposed widening the beam and increasing displacement to correct the problem, but Hoche was too far advanced in construction to allow the necessary changes without breaking up the existing hull structure.

As was customary for French capital ships of the era, their hull featured a pronounced tumblehome shape and incorporated a ram bow.

Marceau was completed with a comparatively light superstructure, but Neptune and Magenta received very large structures that contributed to poor stability.

Marceau was fitted with a pair of pole masts equipped with fighting tops that carried some of her light guns and spotted for her main battery.

[8] For defense against torpedo boats, the ships carried an extensive battery of light guns, though the numbers vary between sources.

Above the belt, the ships had a cofferdam that was filled with cellulose forward; this structure was intended to limit flooding in the event of damage above the waterline.

Additionally, the French Navy continued to build large numbers of ships slowly, which was not a sustainable practice in a period of rapid developments in naval technology.

Admiral Théophile Aube, who was the Minister of Marine in 1886–1887, was a staunch advocate of the so-called Jeune École and opposed new battleship construction in favor of cheaper torpedo boats.

[21] All three vessels were reduced to training ships in 1899, as a number of new pre-dreadnought battleships had been built, taking their place as front-line warships.

Magenta was also struck in 1910, and Marceau became a floating workshop to support torpedo boats and submarines after the start of World War I in August 1914.

She was sold to ship breakers in 1921, but while under tow from Bizerte to Toulon, she ran aground in a storm and could not be pulled free; her wreck remained visible until the 1930s.