It is protocol to be clean-shaven when dressing in British Army uniform, unless the permission of the commanding officer is obtained.
Otherwise, there are only a few exceptions in the Army which allow for servicemen to have a beard, such as skin complaints or for religious reasons.
The service's policy on dress regulations, including facial hair, is, however, "routinely" reviewed, according to an officer speaking in 2018.
Meanwhile, it was confirmed in 2019 that Royal Air Force personnel would be allowed to grow beards for the first time in 101 years, bringing the service into line with the Royal Navy.
Some of the only Army roles allowed a beard on parade include Pioneer Sergeants, Drum Majors, Pipe Majors, Bugle Majors and Goat Majors.
Who is the Pioneer Sergeant?
The Pioneer Sergeant is one of the few positions within the British Army allowed to have a beard when on parade.
Pioneer Sergeants have existed since the 1700s. The tradition began when every British infantry company had one 'pioneer' who would march in front of the regiment.
He would wear a 'stout' apron, which protected his uniform whilst he was performing his duties, and carry an axe to clear the path for anyone following behind.
Watch: A Pioneer Sergeant explains their role.
It was also the Pioneer Sergeant's duty to kill horses that had been wounded in battle.
He would often have to cut off one of the stricken horse's legs so that its rider could receive a new animal - each had a number branded onto its hoof to prevent false claims, such as if a cavalryman had sold his mount.
Pioneers in those times would also carry a sawback sword, pickaxe, billhooks, shovels, and axes. They were traditionally the largest, strongest and most imposing members of the company.
The pioneer sergeant also acted as the blacksmith for the unit. As a result, he was allowed a beard to protect his face from the heat of the forge.
Nowadays the Pioneer Sergeant is usually responsible for carpentry, joinery and similar types of work.
In modern parades, Pioneer Sergeants still wear their ceremonial aprons and carry their traditional axes, which act in place of a bayonet.
That is not to stay there aren't exceptions to the rule though. Other Army members can sport a beard in certain circumstances.
Soldiers can grow a beard for medical reasons, such as in the case of a temporary skin irritation, or, more commonly for religious reasons.
It is prohibited, for example, within the Sikh religion to cut one's hair. As a result, Sikh personnel within the British Army are allowed to have beards.
While Bugle Majors do not grow a full beard, tradition requires a 'full set' moustache with large sideburns, but no hair on the chin.
In British military parlance, a full-set means moustache and side-burns, not a full beard.
Meanwhile, Drum Majors and Pipe Majors are also permitted facial hair, as are Goat Majors.
Click here to read what the military's regulations say about facial hair across the tri-services.
Cover image: MOD.