"Never in the field of human conflict has so much been owed by so many to so few" were the words Winston Churchill famously used to pay tribute to the pilots who fought to prevent a German invasion. Roger Wright completes our three-part series looking back at the Battle of Britain

thousands of people gathered at Biggin Hill for the Battle of Britain Open Day on Sunday to help commemorate one of the greatest achievements in Britain's wartime history.

It was Biggin Hill, affectionately known to air force personnel as "The Bump'' which, more than any other location, came to represent our country's defiant stand against the might of Hitler.

Through the hot summer of 1940 it stood in Britain's first line of defence against the Nazis, and the bravery and sacrifice of the men and women who served there ensured the threat of invasion never became a reality.

The history of flying at Biggin Hill goes back to the First World War when an open area of land high on the North Downs near Bromley was identified as a prime site for the Royal Flying Corps' development of wireless communications.

The site was also on the direct route of the first enemy bombers to attack London and in 1917, 141 Squadron became the first operational squadron to be based there.

Between the wars, Biggin Hill grew rapidly as a centre for home defence and as base for two fighter squadrons.

As war loomed again in the 1930s, the airfield took on a strategic role as a sector station in No 11 Group of Air Chief Marshal Sir Hugh Dowding's Fighter Command and, with its technological heritage, had a pioneering role in the development of radar systems.

By September 1939, it was ready for battle: camouflaged, reinforced with ground defence units and home to three fighter squadrons.

At the helm was Wing Commander -- later Group Captain -- Richard "Groupie" Grice, the man who was to serve as an inspirational station commander throughout the Battle of Britain

The first "kill" recorded by a Biggin Hill-based airman came in November 1939. It was the first of more than 1,600 enemy aircraft to be brought down in the first four years of the war, a record unsurpassed by any other station.

Following the Dunkirk evacuation between May and June 1940, Hitler's forces stood just across the Channel. In the build-up to the planned invasion, the might of the Luftwaffe was given the task of wiping out Britain's air defences, targeting radar installations and airfields

Biggin Hill was a prime target, and by the end of August was enduring a series of twice-daily raids which wreaked devastation.

One attack left 39 dead and many injured in a direct hit on an airfield shelter.

In the air, the bravery and skill of the young Spitfire and Hurricane pilots saw them keep the upper hand against the enemy.

During the war, more than 450 Biggin Hill airmen lost their lives.

In early September the focus of the German onslaught shifted to London and the Blitz began.

At Biggin Hill, the fabled 92 Squadron arrived under the command of Flying Officer Brian Kingcome and, side by side with the men of 72 Squadron, ripped into the German attack.

September 15 -- now Battle of Britain Day -- can be pinpointed as the moment when the RAF prevailed and Hitler's plans for invasion were postponed, never to be realised

On October 30 the Battle of Britain was officially over and Biggin Hill had secured its legendary status.

But its fighting role was far from over, and by the end of 1940 it earned the name "the 600 Station" as the number of "kills" continued to rise.

More than 50 decorations were bestowed on service personnel that year, including Military Medals for three courageous WAAFs who remained working at their posts as bombs fell around them. Gradually, the British airmen were joined by comrades from other countries.

It was a gallant Frenchman, Rene Mouchotte, and a Canadian, Jack Charies, who shared the honour of bringing down the 1,000th enemy plane in May 1943. This landmark, which saw wartime austerity momentarily swept aside, was celebrated with a dinner at London's Grosvenor House Hotel.

From June to September 1944, the airmen made way for barrage balloons which formed a defensive ring around London against the new Nazi weapon -- the V1 "doodlebug".

And as the war entered its final phase, Biggin Hill's role changed to that of a Transport Command terminal, shipping freight and supplies into newly liberated Europe.

After peace was declared, the airfield was a base for RAF and Auxiliary Air Force flying until the late 1950s, when it passed over to civil aviation use. The RAF kept a non-flying presence, with its Ground Officer and Aircrew Selection, until October 1992.

Today, replicas of a Hurricane and a Spitfire still stand outside St George's Chapel on the northern edge of the airfield, a memorial to all those brave men and women who served at "The Bump".