It's fancy and the beer stays sparkly, especially compared to when filled in ceramic cups: Drinking glass is popular among Living History Vikings. Some of the most common replicas that can be seen at events are the ones from the Birka graves, fitting the wealthy warrior with silken sashes, buckles from the Baltic area and wide "Rus" trousers. Since the glass replicas often are cheaper than handmade pottery products (and since most people love to be chic when they have the chance), drinking glasses became a common sight at events.
What archaeological reality lies behind those transparent vessels? What do the finds from Birka actually look like, how many are there and what type of glassen goblet would have been the most common sight? Were they produced on the island and if not, where did they come from? Who were the people that received them as gift for the afterlife?
Holger Arbmann - whom we can thank for the find catalogues "Birka I-1" and "Birka I-2" - wrote his thesis on 9th century trade contacts between Sweden and the Carolingean Empire. There he also studied the glass beakers from the Birka graves and put them into six categories A-F. Almost half a century later, Greta Arwidsson re-evaluated the glass finds from the Birka graves and concluded that there should be 9 categories (termed type 1-9) (Arwidsson 1984, pp 203-212). It is her work, published in Birka II-1: Systematische Analysen der Gräberfunde, which I will mainly refer to in the following article.
The descriptions are all taken from Arwidsson's work mentioned above. I only repeated those information which I deem important for the purpose at hand: Giving an impression of what the glass beakers from the Birka graves looked like. The pictures, taken from the SHM's online collection (and which will be added soon), should complement the description to a degree that the overall shape, size and colour should become clear.
The glass beakers that fall into this category are being called "Trichterbecher" which translates to "funnel beaker" (because they are funnel-shaped). This must not be confused with the funnel beakers that gave their name to an entire culture. These latter ones are made of ceramics and date to the Stone Age.
The Birka funnel beakers were made in pale greenish or blueish colours. They could be completely plain or decorated with thick glass threads of the same colour. Sometimes the edge was decorated in a contrasting dark blue or dark green.
That type is called "bauchige Becher mit aufgelegten, einfachen Fäden", i.e. "bulbous beakers with simple, laid-on threads". This kind of beaker is of monochromatic glass and has irregular glass threads laid on which form patterns shaped like bows or nets. Around the neck are some thinner threads laid on horizontally.
"Bauchige Becher mit umsponnenen Fäden (=Reticellafäden)" means "bulbous beakers with reticella-threads". Reticella-threads are threads made of glass with a different, thinner glass thread spun around them in a contrasting colour.
Those beakers can have two colours or more. They have horizontally laid-on, thin threads as well as the reticella-threads going vertically towards the bottom and meeting there. The main body is made of pale greenish or blueish colours, the horizontal threads made of opaque, yellow glass. The contrasting colour of the reticella-threads is a kind of milky-white or opaque yellow. The rim of the beaker is made of a strip of blue or green glass and thicker than the rest. The main thickness is around 1mm.
This type is being defined by a single find from grave Bj 644. It is comparatively small, its profile s-shaped and the main body almost colourless-transparent. The rim is decorated with a wide stripe of dark purple. Some fragments from another grave might belong to this category, too. That second beaker, however, would have been of different colour.
That beaker type might perhaps be the most popular one among the reenactors we have met, probably because it is quite large and very bulbous, and therefore holds quite an amount of liquid. The original was made of dark green glass. The lower half and the bottom are completely covered in button-like bubbles. The upper half and the rim are smooth and thicker than the lower part. The thickness of the beaker is at least 0.5-1mm.
The beaker of type 6 might confuse reenactors who are not familiar with it because to our modern eye it looks so... regular. It is quite small (perhaps some 6cm or so), slightly convex in profile and almost completely colourless and transperant. In a way it really looks just like a small, modern cup. The original was very thin, however: Only 0.5-1mm.
Beakers of that type are straight in profile, the body is made of colourless glass and quite thick (3-3.5mm). What is interesting about it is its decoration which had been ground into the glass. It features motifs like pine cones or pomegranates as well as birds. Some old, porous, green glass is left on the birds' body.
The glass beaker categorized as type 8 only survives as burnt fragments. It was of pale green colour (?) and only 1mm thin. On the upper part are three pairs of horizontal grooves which contain traces of a yellow-white substance, perhaps glass. Judging from the fragments' shape, we might deal here with another type of funnel beaker with a slightly thicker rim.
Only less than a quarter of the beaker's bottom remained when Arwidsson categorized it as its own type. The sea green glass contains a circular, white disk of unknown material. The transition to the beaker wall would have been very smooth. The bottom would have been around 6cm in diameter.
Greta Arwidsson gives us thicknesses for 5 types:
To offer you a feeling of how thick or thin that actually is, I measured the thickness of four different types of drinking glass I have at home:
As you can see, the drinking glass vessels from the Viking Age could be only half as thick as our modern vessels or even less. Now, take a moment to look at your average Guinness pint (or whatever equals something from my small selection) and marvel at how the Viking Age people perhaps did NOT break their glass at every opportunity (or maybe realize that they probably did... who knows...) and how unbelievable it is that it survived the voyages on carts and boats.
(However, a look at some sherds from the Black Earth might give a slightly different impression, see below.)
According to table 24:1 from Arwidsson's article (Arwidsson 1984, p. 206), the following observations can be made:
Glass beakers or fragments of such were found in 43 graves, about half of which were inhumation graves (n=21), the other half cremations (n=22). Some graves contained more than one type of glass beaker. The sex of the buried person has been identified (as far as I know by non-genetical methods) in 32 graves, the sex ratio being 1:4 (m:f). Three of those graves (Bj 644, 735 and 750) were double graves with both man and woman. In the remaining 10 graves the buried person's sex had not been identified.
Type 1 was by far the most common type among the Birka glass beakers with 24 graves containing whole or fragmentary vessels of that category. Type 2 was second, with eight graves having them as grave gift. Three graves contained type 3, two type 4 and types 5-9 were found in one grave, respectively. Nine graves contained glass vessels that could not be ascribed to any of the categories.
Hjalmar Stolpe's investigations in Birka's settlement area, the so-called Black Earth, yielded some glass beaker fragments as well. In the catalogue from 2018, 14 entries can be found in the chapter "Kärl" ("vessels") (Gräslund et.a. 2018, p. 327). Five of these fragments probably belonged to funnel beakers (type 1). Three fragments show evidence of reticella decoration, two are decorated with glass threads of the same colour as the main body, but without a different colour spun around the threads (i.e. no reticella threads). The remaining four show no such decoration and/or have not been categorized as funnel beaker. The colours found among these fragments are light blue, navy blue, green-blue, blue-green, blue-green and white, slightly green, greenish and grey-brown.
For further glass fragments from the Black Earth, I did some superficial research using the SHM's online collection (http://mis.historiska.se/mis/sok/sok.asp). I excluded those entries with a suggested identification different from "glass beaker", i.e. entries that had for example the note "flaska?" ("bottle?") were not included in my list. I also excluded those where the dating was not completely sure. Also, I only collected information on colour, thickness, decoration and those further notes which I found interesting. My aim here was to get a rough impression on the glass material from the Black Earth - that is why I did not search through all glass fragments (which count a few hundreds), but only part of them.
Neither do I have a formal education in archaeology, nor do I deem myself competent enough in this matter to ascribe the glass sherds to any specific type of vessel (especially since there are hardly any pictures available). I felt persuaded to give the odd suggestion, though, based on the information I could find. However, those are not even educated guesses and should be treated as such.
Sometimes, a remark like "type e" could be found in the finds' descriptions. But since it wasn't evident to me whether a certain type of glass beaker or perhaps some other kind of glass object was meant, remarks like this were ignored by me.
This being said, I made the following observations:
Thickness - Out of 106 database entries where I checked the details, 100 had a note on the glass sherd's thickness that was understandable for me. The average sherd's thickness was around 2.05mm (max: 5.71, min: 0.46). The average can be strongly influenced by one very thick or one very thin sherd, so I also checked the median, which lies at 1.74mm.
Colour - Most sherds were of a green colour (43.4%), followed by undyed (15.09%), yellow (13.21%), brown (6.60%), and blue (4.72%). One sherd each or 0.94% was dark green, clear blue, clear green, olive green, black, and white. 11.32% had no colour mentioned (or none detectable at the fragment).
Decorations - In three cases, the description included remarks like "bubble decoration?" or similar, giving associations of Arwidsson's type 5. One time, laid-on decorations in the same colour as the main glass body was mentioned (as in type 2?). In two cases there was some relief decoration.
Sometimes the vessel type which the registered sherd once belonged to has been noted in the database. While browsing through all the registered sherds (and not only my small sample), I found 14 identified as "trattbägare", i.e. funnel beaker, 11 reticella-beaker (type 3?) and one termed "halsbägare", i.e. "neck beaker" (?).
Summing up, a quick look on the glass sherds from the Black Earth suggest that glass beakers of different types were present in the settlement as well. The thickness of the glass varied; it wasn't always as thin as the type descriptions make them appear. Some of Arwidsson's types may be identified. Among the colours, greens, blues, undyed, and yellow seem to dominate.
Let's go back to the graves. As has already been mentioned, about half of the graves were inhumations, half cremations. Of the 21 inhumations, 15 were so-called chamber graves. Most beakers were found in "female" graves (n=28), 7 beakers come from "male" graves and 10 beakers from graves without sex identification.
One might think it safe to assume that so costly a material has only been given to those of higher social status. However, in an attempt to statistically analyse the Birka graves and their contents, Heiko Steuer found that glass was not limited to the very rich graves. Glass grave goods could also be found in graves at the lower end of the "richer grave" spectrum (Steuer 1969, pp. 213 ff., cited in Gräslund 1980).
To get an impression of the grave good distribution among the graves listed in Arwidsson's article from 1984 (Birka II-1, p. 206, table 24:1), I first looked at how many grave goods were present in those graves according to the SHM's online database. The average grave containing a glass beaker contained 24.47 grave good entries in the database. The minimum was two, the maximum 157 entries. The median lay at 17, i.e. most graves had around 17 entries. All graves with more entries than average were inhumation graves.
The number of grave good entries does not necessarily equal the number of grave goods. There may, for example, be three separate entries for what would have been one single shield if the buckle, handle fittings and fittings from the shield's edge are listed separately. However, it is still save to assume that a higher number of grave good entries indicates a higher number of grave goods, of course, and therefore indicates a "richer" grave.
I concentrated on the following categories: items of trade (i.e. coins not used as pendants, scales, weights), items of warfare (weapons, shields), horses and horse equipment, and items that might indicate professional crafts (including textile crafts).
A single needle case or scissor did not make a textile worker for me, nor was a single coin sufficient to make a grave that of a "trader". I decided that I needed at least three artifacts of one of the categories if they alone would be of too general character (everyone needs a scissor now and then) or at least one specialized artifact (like a spindle or weights or a sword) to put a grave closer to any of the categories mentioned above.
It turned out that none of the cremation burials could be ascribed to any of the categories. This was mostly due to the general lack of grave goods and the ones present being mostly jewellery. Inhumation graves other than chamber graves also lacked sufficient material. Among the chamber graves it happened that items of more than one category could be found, i.e. a grave could contain weights and a scale as well as weapons and crafting tools.
In seven graves items of trade could be found. Weapons were present in seven graves (party deviating from the previous seven). Five graves contained horses or horse equipment. In three graves crafting tools like a crucible, hammer heads or a rasp could be found and in two graves more than three textile tools.
To my eye, there doesn't seem to be a pattern concerning who got a glass beaker into the grave, at least not when using those categories. It seems to be just another nice, posh thing to have in ones grave.
A note on looking at graves - The diversity of things laid down in Viking Age graves is staggering and in many instances we might never know why they ended up there in the first place. Grave goods might have been personal items that the deceased carried during their lifes, but they could just as well have been specially made for the funeral, carrying more of a symbolic than a personal meaning. In some cases, they might symbolize a specific role the individual might have had in society - or would eventually have had, as in the case of a young boy from the Ihre grave field on Gotland who after death was equipped with a full set of weapons, some of which would have been to big for him to carry, as well as a dog and horse (Stenberger 1942). Instead of being a reflection of reality - in this case a "youngster warrior" with too large weapons - grave goods might reflect a social role the deceased's relatives wanted to be associated with (Toplak 2018, p. 72) or perhaps a role they would have liked their children to fulfill in the future.
The topic is quite difficult in itself and we should always keep this difficultly in mind when trying to ascribe certain social categories to the dead based on their grave goods.
I could find datings for 26 of the glass beaker graves using oval brooches (Jansson 1984), combs (Ambrosiani 1984) and the information given in Birka III, pp. 176-179 (Geijer 1938).
13 dated to the 9th century, two to the transmission period (end of 9th/beginning of 10th century) and 11 to the 10th century. Most funnel beaker date to the early period or 9th century; only two date to the 10th century. The reticella beaker of type 3, the bulbous green "bubble beaker" of type 5, the uncoloured, undecorated beaker of type 6 and the fragmentary type 9 date to the 9th century as well. Type 2 (bulbous beaker with laid-on glass threads), type 4 from Bj 644 as well as the colourless beaker with ground-in decoration from Bj 825 date to the later period or 10th century.