This list of town walls in England and Wales describes the fortified walls built and maintained around these towns and cities from the 1st century AD onwards. The first town walls were built by the Romans, following their conquest of Britain in 43 AD. The Romans typically initially built walled forts, some of which were later converted into rectangular towns, protected by either wooden or stone walls and ditches. Many of these defences survived the fall of the Roman Empire in the 4th and 5th centuries, and were used in the unstable post-Roman period. The Anglo-Saxon kings undertook significant planned urban expansion in the 8th and 9th centuries, creating burhs, often protected with earth and wood ramparts. These burh walls sometimes utilised older Roman fortifications, and themselves frequently survived into the early medieval period. The Norman invaders of the 11th century initially focused on building castles to control their new territories, rather than town walls to defend the urban centres, but by the 12th century many new town walls were built across England and Wales, typically in stone. Edward I conquered North Wales in the late 13th century and built a number of walled towns as part of a programme of English colonisation. By the late medieval period, town walls were increasingly less military in character and more closely associated with civic pride and urban governance: many grand gatehouses were built in the 14th and 15th centuries. The English Civil War in 1640s saw many town walls pressed back into service, with older medieval structures frequently reinforced with more modern earthwork bastions and sconces. By the 18th century, however, most town walls were falling into disrepair: typically they were sold off and demolished, or hidden behind newer buildings as towns and cities expanded. In the 20th century there was a resurgence in historical and cultural interest in these defences. Those towns and cities that still had intact walls renovated them to form tourist attractions. Some of Edward I's town walls in North Wales were declared part of the internationally recognised UNESCO World Heritage Site. Urban redevelopment has frequently uncovered new remnants of the medieval walls, with archaeological work generating new insights into the Roman and Anglo-Saxon defences.