While Allies during the years of the Crimean war by 1858 political relations between Britain and France were once more deteriorating as Emperor Napoleon III was building up a French Empire over seas and wished to dominate Europe.
        Having used, and seen the effectiveness of, steam powered ironclad barges during the Crimean war, especially by their performance against Russian defenses at Fort Kinburn at the mouth of the Dnieper River, and with their experiments in early 1857 with rifled guns, the French decided that armor was necessary for their next class of warships.
        Designed by Stanislas Dupuy de Lome the La Gloire was laid down in April 1858, at Toulon, to be launched 24 November 1859 and completed August 1860.  She was essentially a modification of his design for the world's first steam screw warship Napoleon, of 1850.  Originally barquentine rigged but this was later changed to a full rig.          With its completion La Gloire made obsolete the unarmored ships-of-the-line that had previously dominated the seas, but she herself was designed to operate as a battleship in a traditional battle line.  All other maritime nations would be forced to follow suit and build ironclads.  
        Because of their relatively weak industrial base French industry wasn't capable of producing sufficient iron for the hull the La Gloire's was built of wood, although the hull was sheathed in plates of iron measuring from 41/3 to 42/3 inches in thickness, as were her two sister ships.  Her active service was relatively brief due to her wooden hull deteriorated relatively swiftly as it proved to be made of unsound timber.
        This error of wooden hull in  construction continued for many years, and in the building of many ships.  This had the effect on France's ironclad program as the deterioration of the wood covered by iron plating made repairs frequent and increased expense.  The fourth ironclad constructed by the French was the Couronne who had an unusual hull design, of multi-layered iron and wood construction.  The outer hull was 4 inches of iron covered a wooden hull of 4 inches of teak, laid over a framework of 1 1/2-inch-thick iron, over 11 inches of teak, this was covered in a final inner hull of 3/4-inch iron.  This  hull design became the standard of French naval design until later in the century when they introduced iron hulls.
        She served in the French fleet for nine years before undergoing a thorough overhaul, refited, and rearmed.  In 1879 she was removed from the French Navy's warship lists and scrapped in 1883.  (Here sister ships were built with poor rotten timbers.  Due to this Normandie was scrapped in 1871 and Invincible in 1872.)
    No sooner had Gloire been laid down than the Admiralty promptly ordered two ironclad and four iron ships of their own.  With the launch of the first of these, HMS Warrior within the year, the La Gloire was obsolete.  
Statistics
    sister ships:
            Invincible laid down Toulon May 1858, launched 4 April 1861, completed March 1862
             Normandie laid down Cherbourg 14 September 1858, launched 3 October 1860 completed 13 May 1862
    displacement           5,630 tons
    length                      256ft (77.8m)
    beam                      56ft (17m)
    draft                       28ft (8.4m)
    speed                     13 knots
    armour                    4.3-4.7" (107.7-120mm) belt
    conning tower         4" (102m)
    boilers                    8 oval boilers
    machinery                single shaft HRCR (horizontal return), 2,500 HP
    coal  capacity          665 tons
    armament                36 x 6.4 inch(163mm) rifled muzzle-loaders model 1858/60
        refitted in 1866    8 x 9.4 inch (239m) and BL model 1864
                                   6 x 7.6 inch BL model 1866
    crew                       570