At the height of the Seven Years' War, Great Britain made an audacious strike at the heart of Spanish colonial power in the Caribbean. Gathering troops from bases in Britain and Canada and sailing across the Atlantic in secrecy was an incredible feat. The raid on Havana took Spanish colonial forces completely by surprise and following vicious fighting, the city defences at El Moro collapsed. Havana, the jewel in the Spanish colonial crown, now belonged to Britain. The success of the raid influenced British military policy for centuries as the true potential off amphibious warfare was realized.