Berwick-upon-Tweed ) or simply Berwick is a town in the county of Northumberland and is the northernmost town in England, on the east coast at the mouth of the River Tweed. It is situated 2.5 miles (4 km) south of the Scottish border.Berwick-Upon-Tweed, the former county town of Berwickshire, had a population of 11,665 at the time of the United Kingdom Census 2001. A civil parish and town council were created in 2008.Founded during the time of the kingdom of Northumbria, which was part of the Heptarchy, the area was central to historic border war between the Kingdoms of England and Scotland for centuries; the last time it changed hands was when England reconquered it in 1482. Berwick remains a traditional market town and also has some notable architectural features, in particular its defence ramparts and barrack buildings.