The Battle of the Downs was a major naval battle of the Dutch Revolt which was fought off the Kentish coast in 1639.
Dutch sea power was a thorn in the side of the Spanish, especially in the form of commerce raiding. In 1628 Dutch privateer Piet Heyn seized a Spanish fleet laden with silver from the mines in Peru, possibly the most valuable prize ever captured at sea. The Dutch navy also threatened to cut Spain's sea communications with the Spanish Netherlands. In 1639 the Spanish sent a large fleet of warships under Admiral Antonio de Oquendo toward the Spanish-held port of Dunkirk. Dutch admiral Maarten Tromp, with only 13 heavily-gunned ships, intercepted the Spanish fleet, attacking with such ferocity that they were forced to seek refuge in neutral waters off the English coast. Tromp kept the Spanish under surveillance until reinforcements had arrived from the United Provinces. On 31 October, hemmed in close to land, outgunned, and unable to maneuver, the Spanish were slaughtered. Like the Armada conflict of 1588, the battle demonstrated the inability of the Spanish to adapt to teh notion of ships as mobile gun platforms - their vessels were packed with soldiers waiting for a chance to board enemy ships that never came. The Dutch victory ensured that Spain would be eventually forced to recognize Dutch independence, which it did in 1648.