Williams unbuttoned his uniform jacket and pulled up his shirt to reveal a large patch of scar tissue that ran up the left side of his torso. ‘Got caught a little too close to an incendiary on a trip to the seaside.’

Knox was momentarily transfixed by the swirls of flesh that stretched up towards his new dining companion’s chest and down towards his hip.

‘I like to think of it as my own, personal Van Gogh. Maybe I should get it painted,’ Williams joked as he tucked his shirt back in.

Knox pulled back the thick lock of hair that he’d started to let fall over his forehead, revealing the wide scar that stuck out from his hairline. ‘Goes all the way back,’ he said.

‘Normandy?’ Williams asked.

Knox shook his head. ‘Afterwards. I was on a patrol outside Rouen, looking for German stragglers. We got word there might be some holed up in the roof of an old manor house. It was late, and everyone was tired, so I volunteered to take a look. They were there, alright. Two young Germans who had been surviving on God knows what for weeks. One of them was too frail to do anything, the other decided to put me through a wall to protect his friend.’

‘What did you do?’

‘Lay half concussed in a pool of my own blood while the rest of my company came to the rescue.’

They shared more war stories over dinner and another two bottles of wine. And for the next week they spent every day together, dining, drinking, and touring the city.

Months later, demobbed and uninterested by the prospect of restoring his family’s pile to its pre-war state (it had, like many country homes, been taken over by the military for the duration of the war), Williams looked up Knox in London.

Knox introduced him to Holland over a long dinner and drinks at the Garrick Club, where Holland was a member. Williams fitted the rarefied surroundings more than Knox ever had, but his irreverence for them still shone through. Holland liked him, and by dessert they were discussing his prospects. Within a week Williams was cleared to join MI5. From that point Knox and Williams trained together, worked together, and spent most of their free time together. Then, after fourteen years of friendship closer than Knox ever thought he’d experience in his life, he got Williams killed.

In 1959, President de Gaulle decided to pay a visit to Prime Minister Macmillan. Freshly elevated to the highest office in France, de Gaulle felt he deserved all the pomp his new title would afford him. It was to be a state visit.

He sailed across the Channel aboard the Surcouf, one of the French navy’s new T 47-class destroyers, passing within ogling distance of the naval shipyards in Plymouth so everyone there could get an eyeful of the latest symbol of France’s post-war resurgence, before arriving in Southampton.