coastal village, Berwick-upon-Tweed borough, administrative and historic county of Northumberland, England. The site is dominated by Bamburgh Castle, which stands on a cliff 150 feet (45 metres) above the North Sea. The fortress was founded in the 6th century by Ida, first monarch of the Anglo-Saxon kingdom of Bernicia, and subsequently remained the principal stronghold of the kings of Northumbria and then of their feudal successors, the earls of Northumberland. It was rebuilt after the Norman Conquest (1066), and its keep and later walls still dominate the village. The parish church—dedicated to St. Aidan, who founded the original building and died there in 651—became an Augustinian monastery (1121). Pop. (2003 est.) 440.