There was something unusual about the fresh-faced groom that day.
The priest at the San Jorge church in A Coruña, north-western Spain, didn't see anything special, and the smattering of relatives in attendance weren't saying anything.
But both 'Mario' and his bride, Marcela, were women.
It was 1901, and the union between Elisa and Marcela remains the only known same-sex marriage in the history of the Spanish Catholic Church.
But the couple's sweet victory over the conservative culture of early 20th Century Spain would be short-lived.
They were to spend the rest of their lives on the run from persecution across two continents.
Now Elisa and Marcela's story is to be made into a film by Isabel Coixet, whose latest movie The Bookshop, with Emily Mortimer and Bill Nighy, is soon to be released in the UK.
"When I think about these two women and the courage it took for one of them to pretend to be a man, it was unbelievably brave," Coixet, who also wrote the script, told the BBC.
"I was fascinated the first time I heard about the story, which almost raised more questions than it has answers.
"We don't know what happened to them in the end, and how did they think they would get away with it?"
Elisa Sánchez Loriga and Marcela Gracia Ibeas first met while training to be school teachers in A Coruña, and they fell in love.
Because of family concerns about the relationship, Marcela was packed off to Madrid for a spell by her mother.
But, according to the historian Narciso de Gabriel, who wrote a book about the couple, the pair were eventually posted to village schools just a few miles apart in rural Galicia - close enough for Elisa to walk to Marcela's house every evening after classes.
At some point during this period, the couple hatched their elaborate wedding plot.
First, they let it be known that they had quarrelled. And Marcela, who, according to Mr De Gabriel, was pregnant with an unidentified man's child, announced that she was to marry Elisa's cousin.
Enter 'Mario', who purported to be a young man with family ties to A Coruña, but who had been brought up in London in a family of atheists.
Posing in short hair and a morning suit as Mario, Elisa was duly baptised and married to Marcela on the same day.
Mr De Gabriel told the Spanish newspaper El Mundo in 2011 that the "wedding still stands as legal" in A Coruña's civil register.
Sadly for the happy couple, though, their wedding portrait was to make its way to the front page of the local newspaper, La Voz de Galicia.
It exposed their ruse under the headline "A wedding without a groom".
Their unwanted public notoriety made it impossible for Elisa and Marcela to make a living in Galicia, so they fled to Porto in Portugal, where Marcela gave birth to a daughter.
Threatened by an extradition order to face trial in Spain and briefly jailed, the couple managed to board a ship across the Atlantic, settling in Buenos Aires in 1902.
Elisa appears to have married a wealthy old Dane, but he ended up denouncing her intentions as fraudulent.
After that, the trail of the couple went cold for Mr De Gabriel, except for Mexican newspaper reports from 1909 saying that Elisa had committed suicide in Veracruz.
While civil weddings between gay and lesbian couples have been legal in Spain for over a decade, LGBT campaigners in the country still say there are some echoes of the present day in the Elisa and Marcela's struggle.
Inmaculada Mujika Flores, a sociologist, psychologist and director of the Bilbao-based LGBT association Aldarte, welcomes the film project as a rare opportunity to make lesbian relationships more visible.
"If this story had been about two gay men, I'm sure it would be better known," she says.
"We lesbians have virtually no role models in Spain among politicians, actresses or artists.
"Even when there was repression under Franco, it was gay men who suffered, while we have always been invisible. Only when we started to protest in the 1980s, did lesbians begin to exist in Spain."
Ms Mujika Flores says that the legal equality the gay community enjoys in Spain is extremely important to prevent the "pain of being a non-person" - as was surely experienced by Elisa and Marcela.
"But a law doesn't automatically flick a society's switch.
"There are still people who keep their sexuality secret, and others who marry, for example, but feel they cannot take the statutory leave from work due to embarrassment or a fear of being fired."
Coixet agrees that her subject matter is unusual, although she says her intentions are not political.
"It's true that there are very few stories about women in love. But this is not a manifesto.
"For me it's natural to write stories about women; then producers keep asking why.
"They never ask a male director why they want to make a film about Dunkirk. But I was asked, 'Why do you want to make a film about two women who got married in Galicia in 1901?'
"Come on, that's heroic, man!"