Hepburn and Hanson, then a wealthy young man about town, got engaged in 1952. He was a gossip columnist's delight, having already been seen 'squiring one of the few actresses posing any real threat to Audrey in the gamine stakes, Jean Simmons'.
Why then did the engagement collapse? It seems Audrey's mum shares the blame with the French novelist Colette and perhaps Hanson himself.
Mother was a Dutch aristocrat who, convinced that her daughter had movie-star quality, thought early marriage would be something of a career impediment.
A more immediate problem came from Colette, who had just sold her most famous story, Gigi, to a Broadway producer but had retained casting approval for the actress in the main role. She spotted Hepburn in Monte Carlo, cried 'I have found my Gigi' and insisted that she be signed up.
Meanwhile, young Hanson 'had made it clear (according to press reports) that he expected a wife to be at home rather than on Broadway' - and the engagement was broken.