Llywelyn ap Gruffudd or Llywelyn the Last was Prince of Gwynedd from 1255 to 1282. After successful campaigns across Wales in 1257, Llywelyn proclaimed himself Prince of Wales in 1258, and was recognised as such by Henry III of England in 1267 as part of the Treaty of Montgomery. He remained in this position until his death in an ambush at Cilmeri in 1282, one of the final events in Edward I’s conquest of Wales.