Burh

A burh (Old English pronunciation:) or burg was an Anglo-Saxon fortification or fortified settlement. In the 9th century, raids and invasions by Vikings prompted Alfred the Great to develop a network of burhs and roads to use against such attackers. Some were new constructions; others were situated at the site of Iron Agehillforts or Romanforts and employed materials from the original fortifications. As at Lundenburh (medieval London), many were also situated on rivers: this facilitated internal lines of supply while aiming to restrict access to the interior of the kingdom for attackers in shallow-draught vessels such as longships.

Burhs also had a secondary role as commercial and sometimes administrative centres. Their fortifications were used to protect England's various royal mints.