Elizabeth I ascended the throne in 1558 and many problems awaited her at the very beginning of her reign. Making peace with the French and securing the legitimacy of her reign against the pretentions of Mary Stuart were brought to the fore. After the conflict with the Scots and the French, she kept Mary Stuart as her prisoner from 1568 and she had her executed in 1587 due to plotting. Her execution was one of the causes for the beginning of war with Spain. Other causes are Elizabeth's sending help to rebels in the Netherlands and accepting the role of their protector, as well as intensive marauding activity of the English privateers led by Francis Drake, whom she even knighted after his circumnavigation of the world. All this led the Spanish king Philip II to the creation of the "Invincible Armada" which was supposed to invade England. Even though it seemed that Spain was superior, more skilful English sailors and privateers with better armed ships brought victory to their country in 1588 in battles along the Channel, partly with the help of wind and Spanish miscalculations. The war lasted until 1604 and it ended without a real winner. During the war, at the very end of Elizabeth's reign, rebellions supported by the Spanish in order to weaken England broke out in Ireland, but the English eventually managed to quell them. In the final years of her reign Elizabeth entered a change in her foreign policy and recognized Mary's son James Stuart as her legitimate successor and she also made an alliance with the new Protestant king of France Henry IV. Even though she had earlier also endeavoured to keep friendly relations with the French by keeping the marriage negotiations with Francis Valois alive, not until Henry's ascending the throne was the alliance with England's traditional enemy made and it lasted up until 1610.