Rachael Blackmore's career is evidence that there's no such thing as an impossible dream

Rachael Blackmore changed everything. She is a pioneer, a groundbreaker and an attitude transformer. To properly contextualise her feats is almost impossible, yet it might best be done by saying Blackmore realised in fact what had once been deemed too fanciful for fiction.

There was a time when the 1944 film National Velvet was regularly shown on television. From one decade to the next, the movie's viewers saw Elizabeth Taylor playing a young girl who pretended to be a boy and rode a horse named The Pie in the Grand National. Hollywood being Hollywood, they stormed past the post in front, only for the victory to be quashed when Taylor fell off her mount just after the line, infringing rule 144 and leading to a medical assessment that revealed her true sex.

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• 'She's got bigger balls than any of the boys' - the making of Rachael Blackmore 

"A girl, ladies and gentlemen!" screamed a radio broadcaster at Aintree. "A bit of a girl clutching the neck of a bandy-legged outsider streaked across the line to win the greatest race in turfdom. A girl wins the Grand National!"