Following the Duke of Sussex’s explosive televised interview to promote his memoir, Spare, one of the key talking points revolves around Harry’s facial hair.

In what’s being called #beardgate on Twitter, the 38-year-old said the Prince of Wales ordered him to shave off his beard before his own wedding in 2018.

Harry revealed he asked permission from the Queen to keep his beard for his wedding, suggesting his older brother was unhappy about the decision.

Harry told ITV’s Tom Bradby: “I think William found it hard that other people told him to shave it off, and yet here I was on my wedding day wearing military uniform, no longer in the military, but thinking as though I – believing as though I should shave it off before my wedding day.”

Some people on social media insist Harry should have been clean-shaven for such a high profile event, while others argue it’s down to the groom’s personal preference.

So who’s correct? We asked grooming and etiquette experts for their take.

“There is no traditional compulsion for men to shave off beards or facial hair on formal occasions,” says Elizabeth Wyse, etiquette advisor at Debrett’s (debretts.com). “The whole beard question is tied up with the military.”

She continues: “Since 1916 beards have been banned (with some exceptions) by the British Army and moustaches only are allowed in the Army, Marines and RAF. The beard, however, is a long-standing Navy tradition.”

But when it comes to modern royals donning uniforms, the same rules don’t necessarily apply.

“Members of the royal family who are expected to wear uniform on ceremonial occasions, even when they are long-retired from service, do occasionally wear beards with Army, Marines and RAF uniforms,” Wyse explains.

“It is, however, an exception from the normal rules, so it is probable Harry would have asked the Queen for permission to wear a beard as a courtesy.”

Celebrity hairstylist and groomer Luke Benson (instagram.com/lukebensonhair) agrees banning beards is no longer the norm in most circumstances.

“I think it’s quite an old school thing to be clean-shaven now, even for work, unless it’s needed for safety reasons – I know that’s the case for firemen, for example” he suggests.

“I definitely think for guys nowadays having a beard or being stubbly on your wedding day is perfectly normal.”

For Wyse, “As long as a beard is kept well-trimmed, it is perfectly acceptable [for a wedding].”

Is it OK for a family member to insist the groom gets rid of his beard – or the bride or groom to dictate a certain look for members of the wedding party?

“Personally, I wouldn’t impose my views even on my own groomsmen, let alone a groom,” says Benson. “I’d expect them to look tidy, but I would also want them to look like themselves and feel as confident as possible.”

Harry described his beard as “almost like a shield to my anxiety”, which Benson says is understandable: “[Shaving your beard is] quite a drastic change if it’s not a style you usually wear, like having a major haircut – which I never recommend before a wedding!”

How can you make sure your beard is in pristine condition when you walk down the aisle?

“My advice for anyone who wants to keep their beard for their wedding day is to keep it well groomed,” Benson says, recommending you time your last full shave before the big day. “Work out how long it takes to grow back to the perfect length if you’re just going to trim it.”

Wyse says extra care should be taken to create clean edges: “Use clippers to keep the beard neat and tidy, and ensure there is no hair on your neck – just on the underside of your jaw above your Adam’s apple.”

If in doubt, head to a barber for help.

“I would recommend going to a professional to get clean-shaven on areas, like the neck or top line of your beard, so it looks perfect,” Benson adds. “The important thing is you feel happy, confident, and most of all, yourself on the big day.”