French cruiser Dupuy de Lome

French cruiser Dupuy de Lome, The first armoured cruiser, Brest arsenal drydock early 1890s

The French navy suffered major defeats at the hands of the Royal Navy during the Napoleonic Wars and subsequently looked for ways to remedy its inferiority. It was thought initially that steam power and iron-plated ships could equalize the field through 'Quality over quantity'  but the British Naval Industry soon built ships with those same qualities and at a much faster rate, so this proved to be a blind alley. During the latter decades of the 19th century, officers of the so-called Jeune Ecole devised a strategy called Guerre de Course, according to which the best way to defeat Great Britan was to destroy its merchant fleet and isolate the British Isles from trade and from the resources of its colonies. As a result, France began to build a series of powerful commerce raiders, fast enough to evade the battleships of the time but with strong enough armour to overcome cruisers and smaller vessels.
Dupuy de Lome was the first of this new breed of warship - The armoured Cruiser.