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
Course of the Colorado River of this water is used for irrigation in the Mexicali Valley, one of Mexico's most fertile agricultural regions. Below the Morelos Dam the Colorado forms the international border for a short distance, between Baja California and Arizona, before reaching the Southern International Boundary at San Luis Rio Colorado, where it crosses entirely into Mexico. For the remainder of its course to the Gulf, the river forms the boundary between Baja California (west) and Sonora (east). "River", however, is a misnomer as the Colorado is dry or small stream most of the year, due to its flow being almost completely exhausted