It's been 77 years since the Battle of Britain — here are 14 photos of the Nazi onslaught in the skies of England

By mid-1940, Nazi Germany had swept over Western Europe, conquering France and holding territory from the English Channel north to Norway.

Late that summer, Hitler and the German Luftwaffe turned their attention to England, with the Nazi dictator aiming to use his air forces to soften up Great Britain for an eventual ground invasion — codenamed Operation Sea Lion.

In its way stood Prime Minister Winston Churchill and the recently formed RAF Fighter Command, which could field the Hawker Hurricane and the Supermarine Spitfire, some of the best fighter aircraft in the world at the time.

The Battle of Britain raged in the skies above southern England from late June until the end October 1940 (though the Germans see that period as part of a larger aerial campaign). Nazi fighters and bombers raked the English countryside, cities, ports, and airfields with bullets and bombs.

On September 15, the RAF achieved a seminal victory, downing 56 Luftwaffe planes while losing 28.

Two days later, Hitler postponed Sea Lion "until further notice." He kept invasion forces at high readiness, but Sea Lion was finally scrapped in February 1942.

Even with the invasion looking less likely, Nazi Germany continued to launch attacks on England — some of which would claim thousands of lives in and around London in a night — carrying out the Blitz from late 1940 to mid-1941, when Hitler redeployed his air forces to participate in the invasion of Russia.

SEE ALSO: 72 years ago, the Allies beat back the last great Nazi offensive — 16 photos of the Battle of the Bulge

Field guns are pictured in preparation to defend against possible invasion, with nonstop training in all kinds of warfare going at military centers all over Britain, July 9, 1940. During training, a mimic battle was held during which a creeping barrage was laid down and machine-gun nests and other strong points were attacked.

A dead German pilot lies among the wreckage of his Ju 87 Stuka dive bomber, which was brought down over Sussex during the Battle of Britain, in August 1940.

Skies over England are the broad canvas on which are painted the picture of war. Here, a German raider wheels through bursts of antiaircraft fire above a southeast coastal area in England. At the right, a barrage balloon falls in flames during the same August 11, 1940, attack.