HMS Powerful was an 84-gun second rate ship of the line of the Royal Navy, launched on 21 June 1826 at Chatham Dockyard. From 1 January 1839 to the end of 1840 she was commanded by Captain Charles Napier, mainly in the Mediterranean and for much of the time as lead ship of a detached squadron under Napier's orders. On the evening of 29 May 1839 she was anchored in the Cove of Cork, Ireland when Napier received urgent orders from the Admiralty to proceed at once to Malta in view of the imminent probability of war with Egypt. He was also informed that the ships-of-the-line HMS Ganges and HMS Implacable had already started from England. Wishing to overtake them, Napier set sail at 2 a.m. on the 30th for Gibraltar. Powerful arrived at Gibraltar on 12 June to hear the other two ships were three