Fortifications have existed since before recorded history and the Middle Ages were no different. Forts and castles were used throughout the Middle Ages as a means of controlling territory and could even be used in an offensive manner such as the English under Edward I used in the conquest of Wales in the twelfth century.
           Most of the fortifications used in the early medieval period were Roman works that had survived the fall of the empire. Most surviving Roman fortifications were town walls and even if they did not survive completely they were incorporated into new construction whenever possible.