The Principality of Wales (Welsh: Tywysogaeth Cymru) existed between 1216 and 1536, encompassing two-thirds of modern Wales during its height between 1267–1277. For most of its history it was "annexed and united" to the English Crown. However, for a few generations, specifically the period from its foundation in 1216 to Edward I's completion of the conquest of Wales in 1284, it was de facto independent under a Welsh Prince of Wales, albeit one who swore fealty to the King of England.