St James' Day Battle (also known as St James' Day Fight, the Battle of the North Foreland and the Battle of Orfordness) took place on 25 July 1666 — St James' day in the Julian calendar then in use in England (4 August 1666 in the Gregorian calendar), during the Second Anglo-Dutch War. It was fought between fleets of England, commanded jointly by Prince Rupert of the Rhine and George Monck, 1st Duke of Albemarle, and the United Provinces commanded by Lieutenant-Admiral Michiel de Ruyter. In the Netherlands, the battle is known as the Two Days' Battle.