1039AD: Gruffydd ap Llywelyn, son of Llywelyn ap Seisyll and great-great-grandson of Hywel Dda took the throne of Gwynedd and Powys. Soon after, he defeated a Mercian army at Rhyd-y-Groes near Y Trallwng/Welshpool.

Next, Gruffydd moved to conquer Dyfed and in 1041AD, he defeated Hywel ab Edwin at the battle of Pencader thus driving Hywel out of his former kingdom. Hywel is recorded as returning 3 years later whereupon Gruffydd defeated and this time killed Hywel.

Gruffydd ap Rhydderch, King of Gwent, was successful in expelling Gruffydd ap Llywelyn from Deheubarth in 1047AD and resisted his attempts to reconquer the south west until 1055AD. In the same year, Gruffydd ap Llywelyn allied himself with the Mercian earl Ælfgar.

Ælfgar had been stripped of the earldom of East Anglia by Harold Godwinson (yes, that one). Gruffydd and Ælfgar marched on Hereford where they defeated the defenders led by Ralph the Timid and sacked the city. Shortly afterwards, Ælfgar was restored to his earldom.

Having seized Morgannwg and Gwent as well territories along the border, Gruffydd defeated another English army near Y-Clas-ar-Wy/Glasbury, Powys. In 1055AD, he now claimed sovereignty over the entire country as King of Wales, a claim recognised by the English too.