In 1501, Gibraltar passed back to the Spanish Crown, and Isabella I of Castile issued a Royal Warrant granting Gibraltar the coat of arms that it still uses today. In 1704, during the War of the Spanish Succession, a combined Anglo-Dutch fleet, representing the Grand Alliance, captured the town of Gibraltar on behalf of the Archduke Charles of Austria in his campaign to become King of Spain. The occupation of the town by Alliance forces caused the exodus of the population to the surrounding area of the Campo de Gibraltar. As the Alliance's campaign faltered, the 1713 Treaty of Utrecht was negotiated and ceded control of Gibraltar to Britain to secure Britain's withdrawal from the war. Unsuccessful attempts by Spanish monarchs to regain Gibraltar were made with the siege of 1727 and again with the Great Siege of Gibraltar (1779 to 1783), during the American War of Independence.