In a way, I feel as though I don't have a dog in this particular fight. I am small-breasted, and going without any kind of breast support beneath my clothes (period or modern) doesn't really bother me unless the garments are translucent or I have to engage in athletic activities. But I know that going without support is not an option for most women, and I would like to know how the Migration Period and Viking Era northern Europeans handled this issue. Roman era women wrapped their breasts with a long band of linen or wool, called a mamillare or strophium. About a year ago, I made one for myself, along with a matching linen loincloth, as I discuss here on the MedCos site. (Click the button that says "Login as a guest" to see the discussion without setting up an account on MedCos.) This woman bravely displayed her mamillare, which she made from wool instead of linen, in action. She says that using wool is both comfortable and non-itchy; apparently the greater stretchiness of wool is perfect for this particular use.
Long ago, I had gotten accustomed to the idea that there is no evidence for the wearing of female breast support in European costume between the fall of the Roman Empire and the rise of the corset. However, I recently discovered two pieces of archaeological data which might suggest that mamillares were worn in northern Europe.
The first piece of evidence I owe to pearl. In the course of a discussion on her LiveJournal, someone provided a link to an article describing a very recent analysis of the Huldremose find which turned up some plant fibers from the body of the buried woman in addition to the well-known wool skirt and scarf. The article suggests that these fibers could indicate that she was wearing an undergarment of some kind below her other clothing.
The second piece of evidence comes from Birka; I learned of it from Hilda Thunem's excellent discussion of Viking women's shifts. Thunem notes that grave 987 at Birka contains a fragment of plain, unpleated linen that was found in addition to a pleated linen fragment believed to be from a pleated shift:
Finally, one of the graves (nr 987) has evidence that might indicate that some kind of undergarment occasionally was worn under the serk. The serk from this grave was pleated, and the linen fragment that is believed to have been part of an inner garment is plain and less finely woven than the serk.Google Translate makes a bit of a hash out of whether the quote from Hägg states that the plain piece was found under the pleated fragment, but I think its translation is meant to convey that the plain piece was found beneath the pleated one. Judging by the comment I have quoted from her article, Ms. Thunem, who clearly reads Swedish (as I cannot) agrees.
Över och kring nål och hängselöglor i ena spännbucklan, mycket veckrik, sannolikt goffrerad linneväv från särken. Över det goffrerade stycket, ett mindre stycke slätt, grovt linne, vilket bör komma från ett plagg eller annat textilskikt, som burits under särken och närmast kroppen. Hägt uppe på bröstet, ett litet runt spänne.
Inga Hägg: Kvinnodräkten i Birka, p. 17
These pieces of evidence for use of linen (or hemp, since it is very difficult to distinguish the two fibers in an archaeological context) undergarments are separated in time by more than a thousand years. Moreover, the Huldremose evidence in particular is as likely to have come from a shift as from any other undergarment. Still, it is possible that the Huldremose woman and the woman buried in grave 987 at Birka were both wearing a linen mamillare or breastband. The likelihood that the plain linen fragment in the Birka grave was from a mamillare is greater than the likelihood that this was the case for the Huldremose find, because the finer, pleated piece of linen was likelier to have come from a shift than from a breastband and it seems unlikely that the woman would have been wearing two linen shifts.
EDIT: I have corrected the text above, as per the comment I received, to show that the bog body at Huldremose was not wearing the peplos, but a wool skirt and other garments. The peplos was found nearby, and later in time, without a body associated with it.
I must keep an eye out for odd linen bits in other early period graves, to see whether they shed any further light on this issue.