Five years ago, facial hair was a masculine affectation favoured only by unconventional minorities such as French footballers, real-ale aficionados, gentlemen of the road and Tom Hanks in Cast Away. The vast majority of right-minded men shaved daily. We were still seduced by Gillette’s multi-blade marketing and institutionally prejudiced by middle-class Britain’s longstanding antipathy towards the beard. Stubble was for pouting, knitwear-sporting continentals, while an unfettered facial flourishing was for ecological protestors and other antisocial elements – as well as hopeless anachronisms such as Noel Edmonds.

Five years on, and everything mainstream men thought then about beards – except about Noel Edmonds’ beard – has undergone a paradigm shift. Look around you: there are beards on fashion billboards (H&M’s current campaign includes a real whopper), beards starring in Hollywood films, and beards in bands (Dave Grohl is king of the muso beard). And the beard has trickled down, too: they may be by no means ubiquitous but nonetheless, from Fulham to Fife, well brought-up, youngish men in their droves are unapologetically sporting beards. No longer is the beard verboten, an object of feminine disgust, masculine ridicule and universal suspicion.

How did its remarkable social rehabilitation occur? It is a conundrum so perplexing that tackling it demands you have a beard of your own, for contemplative stroking.

It was in Shoreditch/Hoxton, East London, that shoots of recovery for the British beard first sprouted. Russell Manley is proprietor of one of that painfully self-conscious neighbourhood’s most successful hair salons, Tommyguns – and he’s about to export his brand to Manhattan. Manley reckons the beard’s moment came about three years ago. “Just when everyone else in Britain got into mullets and mohawks, Shoreditch stopped being into them – and you started to see beards. You still see them – and moustaches – around here today. I think they’re popular because they are a counter-strike against that whole metrosexual feminisation of guys.”

The British beard’s breakthrough came in the petri dish of East London, but it took hold in more conventional locales – spreading from the bohemian, self-styled “Shoreditch twats” who read Dazed & Confused to the bourgeois conformists who read GQ – thanks to an entirely foreign influence: the new Hollywood beard. Sicilian-born barber-to-the-stars Carmelo Guastella, who runs London salon Melogy, created Ali G’s horrendous faux-ghetto beard for Sacha Baron Cohen. He points out that today Cohen is just one of a new generation of movie stars who choose to wear beards in his “personal time”; not since the good ol’ days of Burt Reynolds and Kris Kristofferson have so many LA leading men been so free with their facial hair.

“Sacha has grown himself a beard, and it looks good: natural, with no harsh lines. Colin Farrell wears his beard like a statement: ‘I’m a hard man, I’m trouble – so watch it.’ When George Clooney grew his, it didn’t work at all – his chin is too strong. Keanu Reeves often wears quite a full beard, but it’s well looked after – it looks great on him,” says Guastalla.

“Russell Crowe has worn his beard for a while now,” he continues, “and it really works with the shape of his face: it makes his look. I have a client who grew his beard exactly like Crowe’s. He loved it. And that’s the thing: we do emulate celebrities, and celebrities have helped the beard go mainstream.

“Let’s face it, no man grows a beard if his wife hates it, but women are seeing these good-looking, rich, famous guys – Brad Pitt is the ultimate example here – with beards, so they’re not so against them. And the great thing for regular men who have beards is that it’s saying something: ‘I’m no suit – I can wear a beard!’”

George Prest, 33, a creative director at advertising agency Lowe, has been wearing an alarmingly full beard – complete with Messiah-long hairstyle – for about three years. He says: “The only downside was the initial risk of food becoming caught in it, but you learn how to legislate for that. And once you start going to a barber for your trim, it’s much less labour-intensive than daily shaving. The only reason I’ve got a beard is that I can have one – and people do expect me to do a job which is vaguely creative. I often get asked if I’m in a band or something like that.”

Prest is using beards professionally, too. “If a brand wants to portray itself as quirky and slightly left-field, then a beard is a pretty efficient way of signifiying that,” he says. “On the other hand, it’s surprising the number of clients for whom having a bearded man in their campaign would be a complete no-no – there is that residual ‘never trust a man with a beard’ prejudice. I can’t imagine having a bearded Prime Minister, for instance.”

Shoreditch still heaves with beards. But as the conventional masses continue to adopt them, will it fall to the men of Shoreditch to give them the chop, just as they spurned the mohawk? Back to Manley: “Facial hair comes in and out of fashion. It’s cyclical. Everyone at some points flirts with it. But here? Well, they’re still around – but by the summer I think they will have gone, at least for a while.”

Good beards

Jamie Foxx The ultra-sleek thin-line goatee was parodied by Ali G, but on Foxx it just looks cool. This is a beard that says, “Don’t mess with me.”

Dave Grohl Definitely the coolest rocker beard. Grohl’s growth has the rough edge of a man who doesn’t care too much about trimming, but is tidy enough not to be a home for breadcrumbs, soup stains and birds’ nests.

Che Guevara Like his fellow Cuban revolutionary, Fidel Castro, Che had a beard that is instantly recognisable. It sings “power to the people” and is the look most wanted by activists and students, although only Johnny Depp has come close to carrying it off.

Sean Connery This is the beard Bond would have grown had he retired from the service. Neat and tidy but not obsessively so, it has charm, maturity and manliness written all over it. See also George Clooney.

Bad beards

Mark Thompson Not quite a beard, but too many days’ growth past mere stubble. The Crockett and Tubbs fuzz of the Eighties doesn't work with ginger hair and is surely the wrong look for the head of the BBC. Robin Cook made the same mistake.

ZZ Top The beard most likely to be seen at Hell’s Angels chapter meetings. It looks like it should be yanked or used to dust the floor – not a wise thing to do to a man who has a skull and devil tattooed on his back.

Fidel Castro No political leader has a beard like Fidel’s. It is firmly in the Marxist tradition (Karl himself had one like this), but years of self-important speeches have rendered it ridiculous. Worryingly, you can’t imagine what he would be like without it.

Noel Edmonds Maybe it’s the personality behind it, but this beard bristles with smugness. Edmonds has sported this goatee since his days as a DJ, but it should have been binned when multicoloured jumpers went out of fashion.

(Owen Vaughan)