The English name for the area comes from Snowdon, which is the highest mountain in Wales, at 3,560 feet above sea level. In Welsh it is named "Eryri." This could be the Welsh word for eagle, which is" eryr", or it may mean "highlands". In the Middle Ages, Llywelyn ap Gruffudd, who was the Prince of Wales, was called "Prince of Wales and Lord of Snowdonia". In Welsh, it translates to "Tywysog Cymru ac Arglwydd Eryri". Gruffudd's grandfather, Llywelyn Fawr, was called "Prince of north Wales and Lord of Snowdonia."