1241 Treaty of Gwerneigron

Treaty of Gwerneigron was a peace treaty signed by Henry III, king of England and Dafydd ap Llywelyn, prince of Wales of the House of Gwynedd, in August. The treaty brought to an end Henry's invasion of Wales. In it, and the Treaty of London which followed in October, Dafydd agreed to cede large parts of modern-day Flintshire to Henry. The treaty also obliged Dafydd to hand over his half-brother, Gruffudd ap Llywelyn Fawr, to Henry, who promptly imprisoned him in the Tower of London.