[4] Before the experimental adoption of the screw in warships in the 1840s, the only available steam technology was that of the paddle wheels, which, due to their positioning on the side of the hull and the large machinery they required were not compatible with the broadside cannon layout of the battleships.

From 1844–45 the Anglo-French Entente collapsed following the French interventions in Tahiti and Morocco, and the publication of French pamphlets advocating a stronger navy (such as "Notes sur l’état des forces navales" by the Prince de Joinville), leading to an arms race in the naval area.

The Royal Navy had also commissioned a number of steam sloops, HMS Rattler being the first screw-propelled warship to be launched anywhere in the world in 1843.

Another sailing battleship, Sans Pareil, was converted to steam on the stocks and launched in March 1851; she beat Agamemnon into service in November 1852.

In the end, France and Great Britain were the only two countries to develop fleets of wooden steam battleships, although several other navies are known to have had at least one unit, built or converted with British technical support (Russia, Turkey, Sweden, Naples, Denmark and Austria).