The original Sea Fencibles (Fencible being a noun formed from the adjective fencible, a shortened form of defencible), were a naval militia established to provide a close-in line of defence to protect the United Kingdom from invasion by France during the Revolutionary and Napoleonic Wars. Britain's defence rested on two lines: a blockade of French ports provided the first, forward line of defence, and the Sea Fencibles and Martello towers provided the second, coastal, line of defence. The Sea Fencibles lasted from 1798 to its disbandment in 1810, with a break of a few years after the Treaty of Amiens. Later, other countries, including the United States, copied the idea.