Edward the Black Prince the party of Montfort, and Chandos won the Battle of Auray (29 September 1364) against the French. As the leaders of the free companies which desolated France were for the most part Englishmen or Gascons, they did not ravage Aquitaine, and the prince was suspected, probably not without cause, of encouraging, or at least of taking no pains to discourage, their proceedings. Accordingly on 14 November 1364 Edward III called upon him to restrain their ravages. In 1365 the free companies, under Sir Hugh Calveley and other leaders, took service with Bertrand du Guesclin, who employed them in 1366 in
Prince of Wales regard as having been the last native Prince. On 16 September 1400, he was proclaimed Prince of Wales by his supporters, and held parliaments at Harlech Castle and elsewhere during his revolt, which encompassed all of Wales. It was not until 1409 that his revolt in quest of Welsh independence was suppressed by Henry IV. The tradition of conferring the title "Prince of Wales" on the heir apparent of the monarch is usually considered to have begun in 1301, when King Edward I of England invested his son Edward of Caernarfon with the title at a Parliament held in Lincoln.