Anglo-Scottish border English king, Edgar the Peaceful, at his council in Chester. After Kenneth had reportedly done homage, Edgar rewarded Kenneth by granting him Lothian. Despite this transaction, the control of Lothian was not finally settled and the region was taken by the Scots at the Battle of Carham in 1018 and the River Tweed became the "de facto" Anglo-Scottish border. The Solway–Tweed line was legally established in 1237 by the Treaty of York between England and Scotland. It remains the border today, with the exception of the Debatable Lands, north of Carlisle, and a small area around Berwick-upon-Tweed, which was taken
England–Wales border then runs westwards to the River Teme, and follows the river southeastwards through Knighton before turning south towards the River Lugg at Presteigne, which is within Wales. The boundary continues southwards across hills to the River Wye, and follows the river upstream for a short distance to Hay-on-Wye, on the Welsh side of the border. It continues southwards and rises through and across the Black Mountains, following the Hatterall Ridge past Llanthony on the Welsh side and Longtown on the English side, to reach the River Monnow near Pandy. It then generally follows the river, past Pontrilas (in England) and