King James II was commander of the Royal Navy from 1660 to 1674, during the second and third Anglo-Dutch wars, before he became king. The text accompanying the image of his portrait at the Maritime Museum says
He commanded the fleet that routed the Dutch at the Battle of Lowestoft in 1665, the first action of the Second Dutch War, and with less success at the indecisive action at Solebay in 1672. This was the last time that a prince and future monarch directed a fleet in action, and the occasion when his flag-captain, Sir John Narborough recorded his belief that 'no prince upon the whole earth can compare with His Royal Highness in gallant resolution in fighting his enemy...he is general, soldier, pilot, master, seaman [and] to say all , he is everything that a man can be, and most pleasant when the great shot are thundering about his ears.'
He fought at the Battle of Lowestoft in 1665 and the Battle of Solebay in 1672.