Battle near Dunkirk or Battle of the Dunes, June 14, 1658, an episode in Franco-Spanish War and the concurrent Anglo-Spanish War. The French army, under Turenne, faced the Spanish army, led by Don John Joseph of Austria (an illegitimate son of King Philip IV of Spain). English soldiers fought on both sides: The 20,000 French troops were supported by 6,000 English Commonwealth men; the Spanish army of about 15,000 gained further strength with a corps of French rebels of the Fronde under Louis II de Condé and 3,000 English/Irish Royalists, the nucleus of potential army for the invasion of England by Charles II, with Charles' brother James, Duke of York, amongst its commanders. The two hour battle ended with a defeat of the Spanish, who lost about 6,000 men whilst their opponents lost about 500. The Royalist Cavalier regiments left the battle in good order when they and the Roundheads agreed not to shed any further English blood on a foreign battle field. Dunkirk surrendered to Turenne and Cardinal Mazarin handed the city's port over to the Commonwealth.