This week marks the 70th anniversary of the start of the Second World War.

For many older people this provides a moment for personal reflection. Both of my grandfathers are still alive having fought in Europe and the Far East as young men. And for all of us it is an opportunity to honour the heroics of an entire generation.

In Britain’s long and remarkable history – including 943 years without suffering an invasion – the Second World War represented our darkest threat and greatest victory.

It was unequivocally a just and essential war. Nazi Germany was the most appalling challenge to our entire way of life. It brought out all that is most admirable in the British national character and the camaraderie of that time is still remembered fondly by all who lived through it.

Of course other countries made essential contributions – including Russia and America – but it remains Britain’s finest hour. There was a huge cost to our defiance. Most important were the hundreds of thousands of soldiers and civilians who lost their lives. The Second World War also left Britain bankrupt as we risked everything to safeguard our freedom.

People of my age owe a timeless debt to the fortitude and bravery of the people who lived through that era. They were our greatest generation who paved the way for subsequent peace, liberty and prosperity.

There have been subsequent wars and acts of valour, but the greatest legacy of the wartime generation is that my parents’ generation and mine have not yet been required to make an enormous sacrifice on a similar scale to defend our country and its values.