The Battle of Santa Cruz de Tenerife was a military operation in the Anglo-Spanish War (1654–60) which took place on 20 April 1657. An English fleet under Admiral Robert Blake penetrated the heavily defended harbour at Santa Cruz de Tenerife in the Spanish Canary Islands and attacked their treasure fleet. The treasure had already been landed and was safe but the English engaged the harbour forts and the Spanish ships, many of which were scuttled and the remainder burnt. Having achieved his aim, Blake withdrew without losing any ships. Background England, ruled at the time by the Protectorate of Oliver Cromwell, decided to support France in its war with the Spanish Empire in 1654. This intervention was mostly motivated by hopes to profit from the war through raids on Spanish possessions in the West Indies. War was openly declared in October 1655 and endorsed when the Second Protectorate Parliament assembled the following year. An English attempt to capture the Spanish colony of Santo Domingo failed, however, whereupon the English shifted their attention to Europe. One of the prime enterprises became the blockade of Cadiz, which had not previously been attempted on such a scale. Robert Blake was to be in charge and also was to come up with methods that he had used in his previous encounters with the Dutch and Barbary pirates. Blake kept the fleet at sea throughout an entire winter in order to maintain the blockade. During this period a Spanish convoy was destroyed by one of Blake's captains, Richard Stayner. A further six ships were sent from England as reinforcements towards the end of 1656, including George, which became Blake's flagship. In February 1657, Blake received intelligence that the convoy from Mexico was on its way across the Atlantic. Although his captains wanted to search for the Spanish galleons immediately, Blake refused to divide his forces and waited until victualling ships from England arrived to re-provision his fleet at the end of March. After this Blake (with only two ships to watch Cadiz), sailed from Cadiz Bay on 13 April 1657 to attack the plate fleet, which had docked at Santa Cruz de Tenerife in the Canary Islands to await an escort to Spain. Blake's fleet arrived off Santa Cruz on 19 April. Santa Cruz lies in a deeply indented bay and the harbour was defended by a castle, Castle of San Cristóbal (Santa Cruz de