Friends is 25 years old today. So to celebrate, Writer at Large Neil Mackay, unearths 25 stories which tell the history of the most influential sitcom ever made

1 Initially Friends was going to be called Insomnia Cafe. It was inspired by the real-life friendship of creators Marta Kauffman and David Crane. The pair met as drama students and were part of a group of university friends they saw as a surrogate family. The pitch for the show was simple: “It’s about friendship, because when you’re young and single in the city, your friends are your family.” Crane and Kaufmann also wrote the theme song I’ll Be There For You.

2 David Schwimmer was the only cast member to have a part written for him – but he turned it down. Schwimmer’s first love was theatre, and he’d had a bad taste of Hollywood when he ended up waiting tables while trying to get a break on screen. Schwimmer was happily back in theatre when he was offered the role of Ross. Crane and Kauffman had met him in LA and been impressed. He refused. They persisted. Eventually he relented.

3 Matthew Perry knew he had to play Chandler when actor friends started asking him to coach them to audition for the part. Perry had been to primary school with Justin Trudeau, and beat up the Canadian premier because he was jealous of his sporting talent. He was broke when he got the role – his hopes of becoming a professional tennis player dashed.

4 Lisa Kudrow was on her way to becoming a successful scientist when the acting bug bit. Her TV career seemed to be taking off when she was cast as Roz in the series Frasier – but she was fired after four days, and left fearing her career was over. When she auditioned for Phoebe, Kudrow had to read for James Burrows – who’d directed Frasier. She thought she’d no chance – but he thought she was perfect.

5 Courtney Cox had an eclectic career before becoming Monica. She’d studied architecture, but with Stewart Copeland of The Police as a relative she ended up cast in Bruce Springsteen’s Dancing in the Dark video. In 1985, she caused a stir when she said "period" for the first time on US TV in a Tampax advert. She later starred in Ace Venture Pet Detective, and a doomed sitcom called The Trouble with Larry – about a man captured by baboons on honeymoon.

6 Matt LeBlanc auditioned for the role of Joey with a bloody nose and killer hangover. The night before, he’d got drunk. Groggy in the morning, he tripped and smashed his face against a toilet. As Kelsey Miller, author of a new book about Friends called I’ll Be There for You, says: "LeBlanc Joey’d his way into stardom."

7 The creators wanted Jennifer Aniston to play Monica – but even though she was eventually cast as Rachel, the future of her role was in jeopardy. She’d already shot another sitcom called Muddling Through, and there was a risk Aniston would have to honour commitments, meaning another Rachel would have to be cast. Muddling Through was finally canned, freeing Aniston up.

8 When filming started in 1994 nobody liked LeBlanc. In reality, softly-spoken LeBlanc worried Joey was too boorish, but the actor was initially perceived as a swaggering macho man. Schwimmer said: “I thought, ‘oh great, here’s this guy I’m going to have to work with for maybe five years, and he’s f**king Joe Cool Stud’.” They all quickly became firm friends, however – just like the show.

9 The cast hated working with Marcel – Ross’s pet monkey in the first two series. Played by a Capuchin called Katie, Marcel was retired and drifted into TV obscurity.

10 Oprah Winfrey was the first to raise the lack of black actors on Friends. In 1995, in the first big interview with the cast, she said: “I’d like for you all to get a black friend.” The debate about the lack of diversity on the show continues – as do concerns about misogyny and fat-shaming.

11 Homophobia also haunts Friends today. One campaigner edited together every "gay joke" in the show and it ran for 90 minutes. Many are offended by the writers’ treatment of Carol and Susan – Ross’s lesbian wife and her partner. However, in an era when homophobia was endemic, others say that at least there were gay characters in the show – in most other series everyone was straight. Crane, who’s gay, and Kauffman based Carol and Susan on close friends.

12 Friends had a huge cultural impact. It sparked a boom in coffee shops like Central Perk. But its biggest spin-off was The Rachel hairstyle. In Britain alone, some 11 million women got The Rachel cut at one time or another. Kelsey Miller says: “Generational theorists claimed it as the definitive series of Generation X.”

13 The show suffered a backlash when it began to cash in on success. In 1996, Friends paired with Diet Coke in a $30m ad campaign. The ads became ubiquitous – and the cast pocketed cheques for up to $500,000. Over exposure saw ratings decline. One newspaper described it as "The One Where the Show Crosses the Line from Promiscuity to Prostitution".

14 Friends had an incredible roll-call of guest stars. At least 70 big names appeared including George Clooney, Bruce Willis, Robin Williams, Brad Pitt, Winona Ryder, Reese Witherspoon, Sean Penn, Elle Macpherson, Sarah Ferguson, and Richard Branson.

15 Although Ross and Rachel’s off-again-on-again love affair is remembered as the central storyline, in reality the pair were only a couple in 10% of the show’s 236 episodes across ten seasons.

16 Friends was performed in front of a live studio audience and if a joke didn’t work writers would rewrite on set. Producers even asked for a show of hands from the audience to see if certain jokes worked. This meant recordings took hours – often running until 2am, with sleepy audiences switched out mid-way.

17 Producers initially wanted Liza Minnelli to play Chandler’s transgender father – Helena Handbasket. Eventually, they hired Kathleen Turner – and played it for laughs, much to the disgust of trans campaigners today. The best that can be said is that in the Friends era, the rest of society was just as ignorant.

18 September 11 helped Friends bounce back from a ratings slump. When Season Eight began on September 27, 2001, it became the leading show on television. Season Eight also won Friends its first Emmy. Kelsey Miller says the quintessentially New York show “was revived by the tens of millions who turned to it for comfort, distraction, escape, hope”.

19 Although Friends is set in Manhattan, writers decided not to mention September 11. Instead, the atrocity was only referenced visually – with US flags in Central Perk, or stars wearing sweatshirts commemorating New York firefighters. Producers had to reshoot an episode where Chandler jokes about bombs at an airport.

20 By the final season, the cast were earning $1 million per episode making them among the highest-paid stars on TV. They’d started out on £22,500. The cast had been able to make such sums not just because of the popularity of the show, but because – as friends – they negotiated together, never allowing executives to divide and conquer.

21 Friends helped get Donald Trump elected. Friends was essential to NBC viewing figures. When channel boss Jeff Zucker realised the show was coming to an end he needed a replacement hit. Zucker went for a show called The Apprentice – credited with helping Trump’s rise to power.

22 The final episode – The Last One – ended with the entire cast weeping. As filming began on January 16 2004, the stars were sitting on the famous orange couch in Central Perk. LeBlanc said: "Do you realise this is the last coffee shop scene?" They all began crying and filming had to stop until they’d calmed down.

23 Amaani Lyle, who worked for Friends, claimed the writers’ room was a hotbed of racism and misogyny. She said writers fantasised about Joey raping Rachel, and referred to Kauffman as a "c**t". Lyle, who’s black, was fired but took out a harassment suit. She lost when a court found the writers’ behaviour reflected a “creative workplace” in a show dealing with sexual themes.

24 It’s unlikely but there might be reunion. Although Schwimmer says he doesn’t want to see the cast return “with crutches and walkers”, there’s been a spate of classic sitcom remakes, including Roseanne and Will & Grace, which has fuelled speculation that Friends may one day return. As Jennifer Aniston, who "fantasises" about a comeback, says: “Anything is possible. I mean George Clooney got married.”

25 Friends is bigger today than it was in the 90s. It’s the most-watched show on Netflix UK, beating The Crown and Stranger Things. Comedy Central UK paid a "colossal" figure to rerun the series. Back-to-back episodes go out daily, and ratings never falter. Friends continues to air in 135 countries. There’s been many homegrown rip-offs from India’s Hello Friends, to Spain’s 7 Vidas – the nation’s longest-running sitcom. Critics say its success is because it’s the ultimate in unthreatening entertainment "comfort food".