Hundreds of veterans, service men and women, politicians and members of the Royal family gathered at St Paul's Cathedral for a major event marking 75 years since the Battle of Britain.
ITV News' Paul Davies reports:
Marking the occasion, around 40 Spitfires, Hurricanes and Bristol Blenheim bombers took flight from Goodwood Aerodrome in West Sussex, in the biggest congregation of wartime aircraft since the Second World War.
Two of the aircraft used - one Spitfire and one Hurricane - actually fought in the famous battle.
The bombers then dispersed across airfields over the south of England which were used during the conflict, in an aerial display put on as tribute to the 2,936 pilots famously nicknamed "The Few" by then-Prime Minister Winston Churchill, for their efforts in defeating the Luftwaffe.
Throughout the summer and autumn of 1940, some 544 service men and women from Fighter Command died as the RAF engaged in an aerial battle to beat back Hitler's forces.
Surviving members of the key fight took part in the display, despite all now being well into their 90s.
Prince Harry, who was celebrating his 31st birthday, was due to fly in one of the four two-seater Spitfires - but after a mechanical fault on one he gave up his place so 95-year-old Ex-wing commander and Battle of Britain Hurricane and Spitfire pilot Tom Neil could still take part in the occasion.
The event also marked newly-elected Labour leader Jeremy Corbyn's first ceremonial engagement - but drew some criticism when he appeared to remain determinedly silent during the national anthem.
He did, however, shake hands with Prime Minister David Cameron upon his arrival at the cathedral.
Mr Cameron attended alongside President Andrej Duda of Poland and his wife Agata, ahead of talks on the refugee crisis in Europe at Downing Street later this afternoon.