Operation Sea Lion was
Nazi Germany's code name for a provisionally proposed invasion of the
United Kingdom during the
Battle of Britain in the
Second World War. Following the
Fall of France the Nazis expected the British to seek a peace agreement, and invasion was considered as a last resort if other options failed. As a precondition, the proposed operation required both
air and naval superiority over the
English Channel and proposed landing sites, neither of which the Germans ever achieved during the war. A large number of barges were adapted as the proposed invasion fleet, but Sea Lion was postponed indefinitely on 17 September 1940 and never carried out.
The German High Command had no confidence that the plan was feasible, and most historians agree it had little possibility of success.