The first bombs fell on Paris on the night of 3 June. It was the first sign of the German advance and the explosions were the starting pistol for an evacuation of the city.

The Nazi regime had terrorised Warsaw following the invasion of Poland the year before and Parisians were expecting the same treatment: Jews and government officials shot in the streets, girls raped, homes looted and all men of fighting age taken to labour camps. While many Parisians fled – by train, car or even on foot – others carried on with their lives and were widely regarded as fools by those who were leaving.

Paul Clarke was a slightly-built eleven year old and one of the dwindling number of pupils who still attended Paris’ largest English-language school. The school served British children whose parents worked in the city but weren’t rich enough to send their offspring to a boarding school back home. They were the children of embassy clerks, low-ranking military attachés, drivers and others of similar status in private companies.

Since the beginning of May the pupil roll had fallen from three hundred to less than fifty. Most teachers had also gone south or returned to Britain, and the remaining kids – who ranged from five up to sixteen – were now taught a shambolic curriculum in the school’s wood-panelled main hall, overlooked by King George and a map of the British Empire.

By 3 June the only teacher left was the school’s founder and headmistress, Mrs Divine. Her typist had been drafted in as a classroom assistant.

Paul was a daydreamer and he much preferred this emergency arrangement to the years he’d spent seated rigidly amongst boys his own age, getting rapped on the knuckles with a wooden ruler whenever his mind wandered.

The work set by the elderly headmistress wasn’t up to Paul’s intelligence and this left him with time to doodle. There was hardly an exercise book or scrap of paper in Paul’s desk that wasn’t covered with delicately inked drawings. His preference was for armoured knights and fire-breathing dragons, but he could also make accurate drawings of sports cars and aeroplanes.

Presently, Paul’s ink-blotched fingers were pencilling the outline of a French biplane diving heroically towards a line of German tanks. The drawing had been requested by one of the younger boys, at the price of one Toblerone bar.

‘Hey, skinny,’ a girl said, as she flicked Paul’s ear and made him smudge the tip of a propeller.

‘For god’s sake,’ he said furiously, as he looked around and scowled at his older sister.