<P> The Firth of Forth was the border between the Picto - Gaelic Kingdom of Alba and the Anglian Kingdom of Northumbria in the early 10th century . It became the first Anglo - Scottish border with the annexation of Northumbria by Anglo - Saxon England in the mid 10th century . In 973, Kenneth, King of Scots attended the 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 by England in 1482 . It is thus one of the oldest extant borders in the world, although Berwick was not fully annexed into England until 1746, by the Wales and Berwick Act 1746 . </P> <P> For centuries until the Union of the Crowns the region on either side of the boundary was a lawless territory suffering from the repeated raids in each direction of the Border Reivers . </P> <P> Following the Treaty of Union 1706, ratified by the Acts of Union 1707, which united Scotland with England and Wales to form the Kingdom of Great Britain, the Border continues to form the boundary of two distinct legal jurisdictions as the treaty between the two countries guaranteed the continued separation of English law and Scots law . </P> <P> The age of legal capacity under Scots law is 16, while it was previously 18 under English law . The border settlements of Gretna Green to the west, and Coldstream and Lamberton to the east, were convenient for elopers from England who wanted to marry under Scottish laws, and marry without publicity . </P>

Show me the border between england and scotland on the map