After the Battle of St Vincent, 14 February 1797, the British fleet went to Lisbon to refit and was also reinforced during that time. Nelson, now a rear-admiral, was given command of the inshore blockading squadron, which anchored off Cadiz. Making a night raid upon Spanish gun-boats, his barge was attacked by an armed launch, carrying 26 men under their commander, Don Miguel Tregoyen. Nelson had with him only his ten bargemen, Captain Fremantle, and his coxswain, John Sykes. A violent encounter with swords ensued and notwithstanding the great disproportion of numbers, 18 of the enemy were killed, all the rest wounded and their launch taken.

On the left of the picture are six ships of the line. Five sail in line close-hauled on the port tack in port-quarter view, while the sixth and leading ship has come up into the wind to anchor in port-broadside view. The ‘Theseus’, with Nelson's blue flag at the mizzen is the stern-most ship. In the left foreground is a naval cutter in port bow view, while Cadiz is shown to the left in the background, with the anchored Spanish fleet. In the intervening water are a lateen-rigged vessel and a brig in port-bow view, underway.