Last Friday night, Keira Walsh led England out in front of 63,000 fans under the iconic Wembley arch. It was by no means the biggest occasion for this generation of Lionesses or for many women’s teams around the world, but it was the latest in a series of showpiece events that have helped propel women’s football to new heights.

Crowds of this size are becoming the norm, globally. Attendance records have been broken across multiple continents – whether that be at last year’s World Cup in Australia and New Zealand, or at a sold-out Dasharath Rangasala in Kathmandu for Bangladesh’s 2022 SAFF Championship win, or the record crowd for a friendly in Atlanta for the USA’s SheBelieves Cup opener just this fortnight. Whether in Europe, Africa, South America or beyond, the game is attracting the audiences it lacked for so long.

It may come as a surprise to some, however, that none of these official records come close to those seen in the past, history that so many in positions of power and beyond have tried to erase and pretend does not exist, the full stories of which are now finally coming to light.

The 1971 Women’s World Cup is one such example. Its story has been told most recently by Copa 71, an emotional and eye-opening documentary released in UK and Irish cinemas last month. Directed by James Erskine and Rachel Ramsay, it chronicles the tournament, combining TV footage with first-hand accounts from the players themselves.

Held in Mexico a year after the men’s World Cup had taken place there, this “unofficial” competition captured attention with colossal crowds, huge media interest and buy-in from multiple sponsors. Six teams took part – Mexico, Argentina, England, Denmark, France and Italy – with Denmark crowned champions after they beat the hosts in front of over 100,000 people in Mexico City.

Despite the Football Association’s 50-year ban on women’s football having only just lifted, England’s “Lost Lionesses” were present, managed by Harry Batt. Batt was a maverick who dreamed of the sport being professional. He constantly butted heads, however, with the newly formed Women’s Football Association (WFA), who were trying to establish their own national team. Despite the WFA’s resistance, Batt took a 14-player squad to Mexico, the majority of whom were teenagers.

As the documentary illustrates, players were treated like celebrities, photographed everywhere they went. Over the course of three weeks, they lived their lives at the front and centre of Mexican media. They had fans waiting for them at their hotels, attended embassy parties and Mexican TV broadcast each and every one of the games.

The organisers – the Federation of Independent European Female Football – were blocked at every turn. Some of these obstacles contributed to its success. Fifa, for example, prevented them from using stadia affiliated to the Mexican Football Federation, meaning that two of the country’s biggest venues were selected – Guadalajara’s Jalisco Stadium and the famous Azteca Stadium in Mexico City.

The football itself was tough and contentious. England played their two group games against Argentina and Mexico in the space of 24 hours, each a gruelling encounter that led to a host of injuries. Copa 71 documents the fiery semi-final in which Mexico beat Italy 2-1, with the Italians still convinced their two disallowed goals should have stood. The grudges from that match are held to this day.

Perhaps most heartbreaking of all are the stories of what happened when the competing players returned home. There were no celebrations. In England, the tournament received very little coverage. Batt and his wife June were ostracised by the WFA while many of his squad were banned from competing again. They were also subjected to ridicule and misogyny that caused many to leave the game. Carol Wilson, the England captain, tells the tear-inducing story of the time she was invited to dinner at Newcastle United – she brought her father along and he had to watch as she was brought up on stage and mocked for her World Cup exploits. It was an event that left Wilson wanting nothing to do with the sport. Indeed, it took 48 years for the “Lost Lionesses” to reunite.

Copa 71 feels like a dream, the story of a group of trailblazers prepared to take on an establishment that kept telling them no. It is a vision of what the women’s game could and should have been way before the 21st century. Knowledge of the sport’s history and its pioneers are vital and, in bringing the players’ stories to light, this documentary gives them a voice that for so long has been lost.

Get in touch

If you have any questions or comments about any of our newsletters please email moving.goalposts@theguardian.com. And a reminder that Moving the Goalposts runs twice-weekly, each Tuesday and Thursday.

• This is an extract from our free weekly email, Moving the Goalposts. To get the full edition visit this page and follow the instructions.