Charles Martel-class ironclad

By the early 1870s, 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.

[1] By the early 1880s, the very large guns had fallen out of favor in the French Navy, so the remaining four ships, to be laid down beginning in 1880, were redesigned with smaller but equally powerful weapons.

All four ships arranged their main battery in a lozenge pattern with 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).

[2] At the same time, developments with quick-firing guns rendered the generation of French capital ships designed in the 1870s and early 1880s dangerously vulnerable to damage above the waterline.

According to the historians John Jordan and Philip Caresse, Huin's design was approved in January 1885 and work on the two ships, Charles Martel and Brennus, began that year in Toulon and Lorient, respectively.

Aube was a proponent of the Jeune École (Young School), which held that cheap torpedo boats could effectively replace the capital ships that had been the primary component of naval power.

[4] But according to naval historian Theodore Ropp, the decision to cancel the vessels had been made in late 1884, during the tenure of Admiral Alexandre Peyron; while he was not a partisan of the Jeune École, he was also not convinced that further battleship construction was warranted during a period of technological uncertainty.

But Thomas Brassey noted that the ships had been ordered in 1882 and that at least some work on the keel for Brennus had already been completed by October 1884, though Charles Martel had not yet been laid down.

[a] Speaking of Charles Martel, the historian Luc Feron states more plainly, instructing readers to "[not] confuse this one with the 12,000-ton battleship of the 1890 program which was actually built.

The ships would have been protected with compound armor; their belt was to have been 440 mm (17.25 in), but unlike previous French ironclads, it did not cover the entire length of the hull.