England–Wales border point. In 926, Edward's successor Athelstan, "King of the English", summoned the Welsh kings including Hywel Dda of Deheubarth to a meeting at Hereford, and according to William of Malmesbury laid down the boundary between England and Wales, particularly the disputed southern stretch where he specified that the eastern bank of the Wye should form the boundary. By the mid-eleventh century, most of Wales had become united under the king of Gwynedd, Gruffudd ap Llywelyn. In 1055, he marched on Hereford and sacked the city. He also seized Morgannwg and the Kingdom of Gwent, together with substantial territories east of
England–Wales border its residents at the time spoke Welsh. In the late 17th century under Charles II it was added to the Oxford circuit of the English Assizes, following which, according to the 1911 Encyclopædia Britannica, it gradually "came to be regarded as an English county". Under that interpretation, the boundary between England and Wales passed down the Rhymney valley, along Monmouthshire's western borders with Brecknockshire and Glamorgan, so including Newport, and other industrialised parts of what would now generally be considered to be South Wales, within England. The 1911 Encyclopædia Britannica unambiguously described the county as part of England, but noted