At this point, international affairs intervened. Louis XI declared war on Burgundy, and Charles the Bold responded by granting an expeditionary force to Edward IV, in order to reclaim his throne. On 14 March 1471 Edward landed at Ravenspurn in Yorkshire, with the acquiescence of the Earl of Northumberland. Warwick was still waiting for Queen Margaret and her son Edward, who were supposed to bring reinforcements from France, but were kept on the continent by bad weather. At this point, Edward received the support of his brother Clarence, who realised that he had been disadvantaged by the new agreement with the Lancastrians. Clarence's defection weakened Warwick, who nevertheless went in pursuit of Edward. On 14 April 1471 the two armies met at Barnet. Fog and poor visibility on the field led to confusion, and the Lancastrian army ended up attacking its own men. In the face of defeat Warwick attempted to escape the field, but was struck off his horse and killed.