Very good to see that record of the authorities' move to order the grooming of the troops, barely a month before the accession of 'Our dear Queen'. Those strictions against facial hair were relaxed in 1854 when the British expeditionary force sent to confront the Russians had arrived the eastern Mediterranean- as discussed here. viewtopic.php?f=27&t=8809&p=41425&hilit=moustache#p41425
The circumstances of the Crimean campaign and the Indian Mutiny led to officers and men leaving off shaving entirely, ushering in a fashion for sporting a heavy full beard which tailed off over the next fiften years or so, with men who were young in the 1850s retaining their beards for much longer. Even Waterloo veterans were photographed wearing beards. Over subsequent decades, soldiers taking the field for extended periods in Africa and on the Northwest Frontier once again regularly sprouted a full set for the duration of the campaigns.
Initially, the fashion of retaining the full beard must to some extent have been a badge of honour, indicating membership of the community of men who had served in those campaigns, which became a fashion then affected by the wider male population, appropriating the exaggerated masculinity that the veterans' full beard betokened- or, thinking more generously, we might say it started as a gesture of solidarity.
It is interesting to reflect on the current fashion for heavy beards amongst younger men in the main, and beards worn by British soldiers in forward positions in Afghanistan who let their facial hair grow for a number of reasons. Almost certainly there was no conscious connection but, looking back, posterity may offer all sorts of theories.
What the connection was between the post-Crimea/Mutiny fashion and the regulation issued, I believe, in 1860 that required soldiers to leave their top lip unshaven, I am not sure. If the authorities had wanted to curtail the general hirsuteness they could have intervened more specifically. Indeed, by 1860, the fashion was coming in for shaving the chin and leaving the side whiskers supporting the moustaches on either flank, as it were, which persisted into the 1870s. That soldiers should have been required to wear at least, a moustache, may have been an attempt to create a degree of uniformity in the face of a general fashion too widespread to tackle head on. Of course, Horseguards could hardly legislate for those who were only able to produce a sheen of blonde fluff.
I shall be watching with interest to see whether in due course the current bearded fashion also evolves into 'Burnsides' and 'Dundreary' whiskers.