The Treaty of Gwerneigron was a peace treaty signed by Henry III,

king of England The monarchy of the United Kingdom, commonly referred to as the British monarchy, is the constitutional form of government by which a hereditary sovereign reigns as the head of state of the United Kingdom, the Crown Dependencies (the Bailiw ...

and

Dafydd ap Llywelyn Dafydd ap Llywelyn (''c.'' March 1212 – 25 February 1246) was Prince of Gwynedd from 1240 to 1246. He was the first ruler in Wales to claim the title Prince of Wales. Birth and descent Though birth years of 1208, 1206, and 1215 have ...

prince of Wales Prince of Wales ( cy, Tywysog Cymru, ; la, Princeps Cambriae/Walliae) is a title traditionally given to the heir apparent to the English and later British throne. Prior to the conquest by Edward I in the 13th century, it was used by the rulers ...

of the

House of Gwynedd 120px, Flag of Gwynedd The House of Gwynedd is the Royal house of the Kingdom of Gwynedd, in Medieval Wales, and is divided between the House of Cunedda and the House of Aberffraw. History The House of Gwynedd, divided between the earlier House o ...

, on 29 August 1241. The treaty brought to an end Henry's invasion of Wales begun earlier that month. In it, and the Treaty of London which followed in October, Dafydd agreed to cede large parts of modern-day

Flintshire , settlement_type = County , image_skyline = , image_alt = , image_caption = , image_flag = , image_shield = Arms of Flint ...

to Henry. The treaty also obliged Dafydd to hand over his half-brother,

Gruffudd ap Llywelyn Fawr Gruffudd ap Llywelyn ap Iorwerth (c. 1196 – 1 March 1244) was the Wales, Welsh first-born son of Llywelyn the Great ("Llywelyn Fawr"). His mother Tangwystl (c. 1180/1185 – c. 1210) probably died in childbirth. Hostage As a boy, Gruffudd was ...

, to Henry, who promptly imprisoned him in the

Tower of London The Tower of London, officially His Majesty's Royal Palace and Fortress of the Tower of London, is a historic castle on the north bank of the River Thames in central London. It lies within the London Borough of Tower Hamlets, which is separa ...

. Given that Gruffudd was a rival claimant to Dafydd's princeship, Henry reasoned that Dafydd's authority could be curbed by the ever-present threat that Gruffudd might be released and sent to Wales to undermine Dafydd's position. Dafydd promised his and his own heirs' loyalty to kings of England so that in the event of breach he would forfeit all the remaining lands to the king. The king also became Dafydd's heir in case the latter died without living offspring. The treaty effectively prevented Dafydd from pressing his rights to the territories controlled by his father Llywelyn until Gruffudd's death during an escape attempt on 1 March 1244, after which Dafydd invaded Flintshire and recovered his lost territory.

References

* * * R. R. Davies, ''The Age of Conquest: Wales 1063-1415'' (Oxford University Press, USA, December 28, 2000) , {{ISBN, 978-0-19-820878-5, pp. 301–302

Gwern (meaning "Alder") is a minor figure in Welsh tradition. He is the son of Matholwch, king of Ireland, and Branwen, sister to the king of Britain. He appears in the tale of '' Branwen, daughter of Llŷr'', in which his murder at the hands of his sa ...

1241 in England 13th century in Wales 13th century in England Gwerneigron History of Flintshire 1241 in Wales England–Wales relations