In 1592 Admiral Yi-Sun put armor plates on his "tortoise-ships". These protected the sides and top from bullets, arrows and fire. This allowed his small fleet to be victorious in several battles with the ese fleet. The first Western ironclad battleship, "Gloire", was launched by the French Navy in November 1859. The British Admiralty had been considering armored warships since 1856. They prepared a draft design for an armored corvette in 1857. In early 1859 the Royal Navy started building two iron-hulled armored frigates, and by 1861 had made the decision to move to an all-armored battle fleet. After the first clashes of ironclads (both with wooden ships and with one another) took place in 1862 during the American Civil War. It became clear that the ironclad had replaced the unarmored ship of the line as the most powerful warship afloat. This type of ship would come to be very successful in the American Civil War.