The War of the Austrian Succession broke out in 1740, over whether Maria Theresa could inherit the throne of the Habsburg Monarchy. Britain supported Austria and the claim of Maria Theresa, whilst Spain and France supported the rival claim of Charles, Elector of Bavaria. Britain and Spain had been at war in the Americas since 1739, in the War of Jenkins' Ear. Britain and France were not officially at war at the start of 1744, although they were on opposite sides of the wider conflict and France was secretly planning an invasion of Britain.