River Lugg River Lugg The River Lugg () rises near Llangynllo, Powys. It flows through the border town of Presteigne, Wales then through Herefordshire, England, to the south of Leominster where it meets a tributary, the River Arrow. Its confluence with the River Wye is at Mordiford, downstream of Hereford and from its source. Below Leominster the river was made navigable under the "River Wye & Lugg Navigation Act 1696" for improving the River Wye, and had pound locks. Despite several attempts to improve it, including making flash locks against bridges, the river was probably never a satisfactory navigation. Commercial navigation probably
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