Llywelyn ab Iorwerth, also known as Llywelyn the Great, was a medieval Welsh ruler. He succeeded his uncle, Dafydd ab Owain Gwynedd, as King of Gwynedd in 1195. By a combination of war and diplomacy he dominated Wales for 45 years.

The Kingdom of Gwynedd was a Welsh kingdom and a Roman Empire successor state that emerged in sub-Roman Britain in the 5th century during the Anglo-Saxon settlement of Britain.