in the autumn, and Henry withdrew; but Dafydd died unexpectedly in 1246 without issue. His wife, Isabella de Braose, returned to England; she was dead by 1248. Dafydd married Isabella de Braose in 1231. Their marriage produced no children, and there is no contemporary evidence that Dafydd sired any heirs. According to late genealogical sources collected by Bartrum (1973), Dafydd had two children by an unknown woman (or women), a daughter, Annes, and a son, Llywelyn ap Dafydd, who apparently later became Constable of Rhuddlan and was succeeded in that post by his son Cynwrig ap Llywelyn. Owain Goch ap Gruffydd 1246–53 (d. 1282) Following Dafydd's death, Gwynedd was divided between Owain Goch and his younger brother Llywelyn. This situation lasted until 1252 when their younger brother Dafydd ap Gruffudd reached his majority. Disagreement about how to further divide the realm led to conflict in 1253 in which Llywelyn was victorious. Owain spent the remainder of his days a prisoner of his brother. Llywelyn ap Gruffudd 1246–82 After achieving victory over his brothers, Llywelyn went on to reconquer the areas of Gwynedd occupied by England (the Perfeddwlad and others). His alliance with Simon de Montfort, 6th Earl of Leicester, in 1265 against King Henry III of England allowed him to reconquer large areas of mid Wales from the English Marcher Lords. At the Treaty of Montgomery between England and Wales in 1267 Llywelyn was granted the title "Prince of Wales" for his heirs and successors and allowed to keep the lands he had conquered as well as the homage of lesser Welsh princes in return for his own homage to the King of England and payment of a substantial fee. Disputes between him, his brother Dafydd and English lords bordering his own led to renewed conflict with England (now ruled by Edward I) in 1277. Following the Treaty of Aberconwy Llywelyn was confined to Gwynedd-uwch-Conwy. He joined a revolt instigated by his brother Dafydd in 1282 in which he died in battle. Dafydd ap Gruffudd 1282–83 Dafydd assumed his elder brother's title in 1282 and led a brief period of continued resistance against England. He was captured and executed in 1283. Government, administration and law The political maturation of the principality's government fostered a more defined relationship between prince and the people. Emphasis was placed on the territorial integrity of the principality, with the prince as lord of all the