Hello! I wanted to ask you a question for a long time. What kind of underwear do you think women in the First and Second Army possibly wear? I know corsets were not those restrictive monstrosities the modern media likes to depict, but they are not the best choice either when someone has to spend weeks or months at the frontlines actively fighting. The undergarment Alina wore before she was presented to the Tsar is something that existed in the time-period? Thanks in advance :-)
Oh, it's an exciting question!
Okay, to start with Alina's underwear: although we cannot see it properly, the lower part I'm pretty sure is a pair of split drawers--basically shorts where there is a hole at the crotch (for easy bathroom access). Since clearly both in the First and the Second army ankle-lenght skirts are accepted as a part of the official uniform for women, split drawers make sense. When worn with the usual layers, the drawers are under the chemise, or the chemise is tucked into them. Combinations--literally the combination of the drawers and the chemise, basically a romper--came into fashion in the 1870s, to reduce the bulk unde the dress.
The top part is more interesting, because to the question "is it peiod accurate?" my answer is: "yes and no." To me, it looks like a corset cover, which, in itself, is a period accurate piece (although it's a bit more 1900ish than 1880ish)--as the name suggests, it was supposed to go over the corset, to smooth its lines and to provide some extra modesty/warmth. So, basically, it was the third layer from the skin, yet Alina wears it right on the skin--it's kinda like wearing a cami without a bra today. It's not exactly period accurate.
But within the context of the show? It makes pefrect sense! Alina is a poor orphan, and the First Army is not the best when it comes to supplies (plus female soldiers are supposed to be kind of a new thing), so it would be totally okay for her to wear whatever undergarments she can get her hands on.
As for undergarments (or, more accurately: supportive garments/foundation garments) for the female members of the First and Second Armies, we have a couple of options, some are historical/period accurate, some are "it's a fantasy setting, let's see what we can make out of what we have".
1, There were, of course, corsets specifically for sports and for working women--these are usually lightly boned/corded, to allow for greater range of movement.
2, One thing that can also be done, is to take out the busk of the corset--the busk is the rigid, front part of the garment, usually made of wood, steel, or ivory. While the rest of the boning of the corset is made of some more-or-less bendable material (reed, baleen, etc.) that mold to the body with wear, the busk does not bend, so you cannot really bend forward. Take it out--easier movement.
3, That being said, whatever they are wearing, it should either be front-opening with back lacing, or front lacing--so they can dress without any help
4, Outdated for the period that is the closest for the show's setting, but they could wear transitional stays. These are usually short, lightly/unboned supportive garments, worn during the regancy period/under empire style dresses (if it ain't broke...)
5, Jumps are also an uption: originating from the 18th century, these are quilted bodices with little/no boning. Meant to be kind of a lounge wear, they'd also kinda do for the army.
5, Boned waistcoats/stays (also kind 18th century style), worn over a shirt/blouse, but under the kefta. Although a supportive garment, it can be colorful, decorated, and worn as an outer layer!
6, And, like... it's the army. People are broke. Supplies are shit. Go with bindings--take a long piece of cloth and wrap it around yourself. Not really stylish, but will do the job.
7, That being said, let me add something: corecloth corsets.
Also, one thing to remember corsets/stays/jumps are never the first layer. They come over the chemise/shift/combinations, that protect the foundational garment from bodily fluids, and the the skin from the foundational garment.
The Pretty Housemaid corset (c. 1890), cheap and durable, it was specifically marketed towards young women in domestic service. Look at how it has very little boning, and a lot of cording around the hips.
Sports corset from 1890. The only steel boning it has is in the back, to support the lacing, otherwise it's all cording.
Transitional stays, 1790. Although it has some boning, the garment does not extend below the natural line of the waist, allowing for easy movement.
Recreation of another, 1790-1800s style of transitional stays--almost like a modern bra, isn't it?
Early 18th century quilted jumps--it's a bit ragged, but you get the picture.
Another jumps, from c. 1730, in a bit better condition.
Reproduction patterned 18th century stays worn as outerwear.