The major foreign entanglement of this period was the Anglo-Spanish War. In 1654, the English Commonwealth declared war on Spain, and regiments of the New Model Army were sent to conquer the Spanish colony of Hispaniola in the Caribbean. They failed in the conflict and sustained heavy casualties from tropical disease. They took over the lightly defended island of Jamaica. The English troops performed better in the European theatre of the war in Flanders. During the Battle of the Dunes (1658), as part of Turenne's army, the red-coats of the New Model Army under the leadership of Sir William Lockhart, Cromwell's ambassador at Paris, astonished both their French allies and Spanish enemies by the stubborn fierceness with which they advanced against a strongly defended sandhill high.