Soaked in fuel and only freed from his bent BRM by the efforts of his team-mate Graham Hill and Bob Bondurant, the oft-told story of his narrow escape from that terrible crash at the Belgian Grand Prix, and the dumbfounding sequence of events that followed, has taken on a darkly comedic hue over the years – especially the bit about the nuns… But the trauma of what he went through the day after his 27th birthday triggered something deep within Stewart. It became a totem for his campaigning that demanded a fundamental, awkward and uncomfortable change in attitudes from the cold indifference exhibited by race promoters, circuit owners, the governing body – and even some of his fellow drivers.

The horrors largely went unspoken back then. There was the day in September later that same year when Jackie was racing a Ferrari 250LM at Montlhéry when a driver and two marshals were killed. “As I drove out of the pits, I happened to look to my left and see two dead bodies, shattered beyond recognition, lying just a few metres away from me,” he recalled. It was a sight “more suited to a medieval battlefield” than a sporting venue. The following year at Monaco he stood in the pits having retired his BRM staring at the black plume of smoke rising from the inferno that claimed poor Lorenzo Bandini. And so it went on. Stewart made a point of not being superstitious, but during his racing years he could barely glance at a cemetery. He’d leave for a trip to Spa or the Nürburgring checking the rear-view mirror and wonder whether he’d ever see home again. Then at one circuit, he discovered the chief medical officer was a racing enthusiast, but with minimal experience of neurology, burns or internal medicine. He was a gynaecologist. Enough was enough.

Jackie recuperating at St Thomas’s Hospital, Westminster, in June 1966, after his return to the UK in the wake of his Spa accident. The medical facilities at the circuit had appalled him – another detail that inspired his safety crusade