This is the 70th anniversary of the Dunkirk evacuation, where 338,000 British and French troops were carried out of the German encirclement by just about everything that could float.
“Without Dunkirk, Britain wouldn’t have had an Army and it’s extremely questionable whether Britain could have fought the war,” he explains.
Mr Hewitt gives the credit to the Royal Navy and Admiral Sir Bertram Ramsay, who led the operation, but also to all the civilians who helped.
“They thought they would bring back 30-40,000. In the end they rescued 338,000 British and French troops. It’s an extraordinary achievement.”
And this pulling together of civilians and the military meant an event that could have been seen as a failure became, in fact, a key turning point in World War II.
“Dunkirk was a military defeat, but it was a symbolic victory,” he adds.