Gruffydd now allied himself with Ælfgār, son of Earl Leofric of Mercia, who had been deprived of his earldom of East Anglia by Harold Godwinson and his brothers.
•
Bleddyn ap Cynfyn and his brother Rhiwallon came to an agreement with Harold and were given the rule of Gwynedd and Powys.
•
Earl Harold was given the task of counter-attacking, and seems to have built a fortification at Longtown in Herefordshire before refortifying Hereford.
Prior to Norman occupation of lower Gwynedd, the Perfeddwlad, Rhuddlan was the site of a Welsh cantref and served as the seat of government for the Welsh king Gruffydd ap Llywelyn (1007 – August 5, 1063), whose family may have been the traditional Welsh lords of Rhuddlan for generations.
From here the Lords of Rhuddlan commanded the lands of North East Wales (Welsh Perfeddwlad) on behalf of Gruffydd ap Llywelyn (1007 – August 5, 1063), the last ruler of all Wales.
Llywelyn the Last | Rhys ap Gruffydd | Gruffydd ap Llywelyn | Owain Goch ap Gruffydd | Llywelyn the Great | Llywelyn | William John Gruffydd | Morgan Llywelyn | Madog II ap Gruffydd, Lord of Dinas Bran | Madog ap Llywelyn | Madog ap Gruffydd Maelor | Llywelyn the Elder ap Maredudd ap Cynan ab Owain Gwynedd | Llywelyn Siôn | Llywelyn Bren | Llywelyn ap Dafydd | Gruffydd II ap Madog, Lord of Dinas Bran | Elis Gruffydd | Anarawd ap Gruffydd |
In 1055 Ælfgar, the earl of East Anglia, was exiled and allied himself with the ruler of Wales, Gruffydd ap Llywelyn.
On 16 June 1056, a battle was fought at Glasbury between an English force, led by Bishop Leofgar of Hereford, and a Welsh force led by Gruffydd ap Llywelyn, at which the warrior bishop was killed.