Deeply devout, Philip saw himself as the defender of Catholic Europe against the Ottoman Empire and the Protestant Reformation. In 1584 Philip signed the Treaty of Joinville funding the French Catholic League over the following decade in its civil war against the French Calvinists. In 1588 he sent an armada to invade Protestant England, with the strategic aim of overthrowing Elizabeth I and re-establishing Catholicism there, but his fleet was defeated in a skirmish at Gravelines (northern France) and then destroyed by storms as it circled the British Isles to return to Spain. The following year Philip's naval power was able to recover after the failed invasion of the English Armada into Spain.