Llewelyn ap Gruffydd (died 1282), Prince of Wales, is considered the last champion of Welsh liberty and the last effective native ruler.

Llewelyn ap Gruffydd was the son of Gruffydd ap Llewelyn ap lorwrth (died 1244) and Senena. Little is known of his early years. In 1246 he and his elder brother, Owain the Red, succeeded their uncle, Davydd ap Llewelyn, as rulers of Gwynedd in northern Wales. Although he did homage to Henry III the following year and renounced claims to land east of the Conway, he soon broke with the English because of the oppressive raids by the border lords. During the next years he extended his power and by 1256 had expelled the English from northern Wales. Establishing overlordship of all of Wales the following year, Llewelyn in March 1258 took the title of Prince of Wales and tried to make alliances with Scotland.

In 1262 Llewelyn allied himself with Simon...