 Complete the following phrase:  The walls around coastal cities, such as Southampton, had evolved from simpler Norman fortifications by the start of the 13th century. Later, King Edward I was a prolific castle builder and sites such as Conwy Castle, built 1283 to 1289, defend river approaches as well as the surrounding land. Built 1539 to 1544, the Device Forts are a series of artillery fortifications built for Henry VIII to defend the southern coast of England. Between 1804 and 1812 the British authorities built a chain of towers known as Martello Towers to defend the south and east coast of England, Ireland, Jersey and Guernsey against 