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
River Mease River Mease The River Mease is a lowland clay river in the Midlands area of England. It flows through the counties of Leicestershire, Derbyshire and Staffordshire and forms the administrative border between these counties for parts of its length. The river and the lower part of one of its tributaries, the Gilwiskaw Brook (pronounced "jill-a-whiskey") are both protected as "one of the best examples of an unspoilt meandering lowland river". The river receives protection under European Union law as a Special Area of Conservation (SAC); and protection under UK law as a Site of Special Scientific Interest (SSSI). The Mease