“Women are not physiologically capable of running a marathon.”

In 1966, a young woman named Roberta (Bobbi) Gibb applied for an official place in the running of the Boston Marathon, one of the most prestigious marathon races in the world. Her application was refused and, if the person replying to it had left it there, history might well have been different. Instead, he (it was almost certainly a ‘he’) felt obliged to add in the sentence above as a reason for the rejection. For Bobbi Gibb, the rejection was bad enough but the patronising and derogatory comment on her capabilities as a woman made her angry – angry enough to cheat. She determined there and then that she WOULD run the Boston Marathon whether they would let her or not.

In the mid-1960s, women’s long-distance running was still considered dangerously radical. Female runners had completed 26.2 miles many times, but groundless ideas lingered that a woman’s body was not built for such extreme exertion.

The 1928 Summer Olympic Games saw women compete in athletics events for the first time, and on 2 August three of the nine women who ran in the 800m final broke the world record, with Germany’s Lina Radke claiming gold. However, what should have been a giant stride forward for women’s athletics degenerated into a remarkably nasty media campaign in which newspapers worldwide reported incorrectly that many women had collapsed with exhaustion after the race and that such exploits were far beyond the female sex. The New York Times falsely reported that “six out of the nine runners were completely exhausted and fell headlong on the ground”, while the Montreal Star shrieked that the race was “obviously beyond women’s powers of endurance and can only be injurious to them”.

The media firestorm led officials to cut the 800 metres from the women’s Olympics, with the event not appearing again until 1960. Women’s perceived fragility was underpinned by some preposterous medical theories that wound their way into the public consciousness.

Ask Google who was the first woman to run the Boston Marathon and you’ll find the name Kathrine Switzer, along with a photo that appears to show a group of men chasing and manhandling a woman with the number 261 pinned to her midriff.

It is a shocking image that easily fits a narrative of misogyny, but this is not the real story of the first woman to run the world’s oldest continually staged marathon. The truth, as so often, is far from black and white.  Switzer, in fact, had gained her race number illegally by disguising her gender on the application and having her male coach pick it up.

Bobbi Gibb had determined that ludicrous ideas about female capability would not stop her. A few months before the marathon, she applied for a runner’s number to be one of the 540 that would eventually start the race, but was rejected with the now famously curt assessment of women’s physiological capabilities. So she decided just to turn up and run it anyway.

Her mother drove her to the start line on the morning of the race. She was wearing her brother’s Bermuda shorts, with a swimsuit underneath, and a big sweatshirt with a hood that was pulled over her head. After running a few warm-up miles she returned to the starting area, where she did her best to hide by creeping into a set of bushes nearby. When the starting pistol cracked, Gibb loitered, allowing the faster runners to move down the road before joining the moving crowd.

She realised that the men around her knew she was a woman and was afraid that she would be stopped from running. Her fears were unfounded. Instead of hostility, camaraderie quickly flourished. When it became clear she needed to take off her sweatshirt or suffer the heat in it, she expressed her fears of being ejected from the race to the men around her. “We won’t let them,” came their assurance. Buoyed by the companionship, Gibb removed her outer layer and ran freely and proudly – her blonde ponytail swinging from side to side. Spectators lining the street – men, women and children – applauded her as she passed, with news of her participation spreading along the course via radio bulletins.

Gibb was not only blazing a trail, she was doing it quickly. She ran the first 20 miles at a sub-three hour pace, but with her newly-bought men’s running shoes cutting into her feet, her speed began to drop. Her race had changed. Anxiety over being pulled out by officials was now replaced by that feeling all too familiar to any long-distance runner – painful determination and a longing for the finish line. She completed her first Boston Marathon in an impressive three hours, 21 minutes and 40 seconds – faster than two-thirds of the competitors.

Gibb ran the Boston Marathon twice more.

Though it wouldn’t be until 1972 that women were given numbers and allowed official entry, the pioneers had lit a fuse. In 1973, the first all-women’s marathon was held in Waldniel, West Germany, but the 1980 Summer Olympic Games in Moscow came and went, still without a female marathon event. The following year, the International Olympic Committee voted that a female marathon event would be included at the 1984 Olympics in Los Angeles – and it has been ever since.

The effect this has had on women’s marathon running has been dramatic. In the last 60 years, the women’s world record for 26.2 miles has plummeted by an astonishing one hour and 23 minutes. As a comparison, the men’s record has dropped by only 54 mins in the last 115 years.

Bobbi Gibbs’ running exploits have continued to inspire. In 1996, she was finally recognised as an official three-time winner, receiving her medals while also having her name inscribed on the Boston Marathon Memorial in Copley Square.

In 2016, 50 years after that momentous race, Ethiopia’s Atsede Bayisa presented Gibb with her Boston Marathon winner’s trophy after learning of the events of 1966.