Video report by ITV News' Paul Davies
A flypast involving dozens of Second World War aircraft has taken place above Kent today to mark 75 years since the Battle of Britain's "hardest day".
On 18 August 1940, British pilots, engineers and a host of other air and ground staff faced seemingly endless assaults from Nazi Luftwaffe during perhaps their toughest test of the Second World War.
During that Sunday, Hurricanes flown by 32 Squadron and Spitfires flown by 610 Squadron only left the air to refuel and re-arm, as the Germans attempted to batter the RAF's fighter bases to the point of non-existence.
The Nazis sent out 2,200 aircrew flying 850 sorties in that single day, with Luftwaffe wrecks littering parts of Southern England. The RAF itself flew 927 sorties with 600 aircrew.
But while Britain's air force lost 136 aircraft, the day turned out to be a disaster for the Nazis, both in terms of morale and numbers. Nonetheless, there were many casualties on both sides, and neither side would incur more losses on any other day of the battle.
Today, eighteen Spitfires and Hurricanes took to the skies in a remembrance sortie at Biggin Hill, an historic former RAF airfield where hundreds gathered to pay respects to those who risked their lives.
One of those was Tony Pickering, a Battle of Britain pilot who told ITV News' Paul Davies it was good to see the aircrafts, both of which he flew, as well as the "few boys I remember".
Asked what Britain owes him and other veterans, he said simply: "I don't know whether you owe me anything, I had a job to do and I did it.
"I was called upon to do it, my ancestors had done it and I had some comrades who did a jolly good job."