Thor answered the cross – and fell silent

Þyrvé raised the stone in memory of Ôgmundr, her husband, a very good thegn. May Thor hallow.

So it reads on a runestone at Velanda in Västergötland. The last two words, Þórr vígi, ask Thor to hallow the stone. It is one of the clearest pagan invocations on any Swedish runestone – and it has almost no company. Of 2,321 Swedish runestones only six bear Thor's name, his hammer or a picture from the myths about him. A cross or a Christian prayer is found on 1,103. Why is Thor so rare? We followed the six stones through time, through the landscape and among the stones that have been lost.

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What binds the six together?

We went through the 2,321 Swedish runestones in the Scandinavian Runic-text Data Base and looked for pagan and ritual markers: Thor's name in the text, formulas such as Þórr vígi (may Thor hallow) and vígi þessi kuml (hallow this monument), curses, the old magical word alu, and images of Thor's hammer or of Thor fishing for the Midgard serpent.

The first thing that binds them together is the god. All six are about Thor; none names Odin, Freyr or any other god. Thor was the thunder god and the protector, the one who fought the Midgard serpent. In the Icelandic stories of the conversion, too, it is Thor who challenges Christ.

The second is that they borrow from the Christian stone. The hammer at Stenkvista stands where the cross usually stands. The text at Korpbron ends with a bind-rune in the shape of a cross. The stone at Linga has Thor on one side and a cross on the other. And may Thor hallow stands at the end of the text, where the Christian stones have their prayer. The Altuna stone was carved by Balli with two others, and Balli also made Christian stones: 29 of his 76 stones have a cross. Otherwise they are ordinary runestones: they were raised in memory of fathers, a son, a husband, a brother and kinsmen – by sons, a father, a widow and a sister.

A seventh stone belongs to the same picture. At Åby in Södermanland there is a Thor's hammer and perhaps a Thor's mask on an earth-fast boulder (Sö 86). It is not counted among the runestones here, since it is carved on a boulder lying where it has always lain.

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When were they carved?

Five of the stones can be dated by their ornament. Four belong to the two earliest style groups, RAK and Fp, the time up to about 1050. The fifth, the Altuna stone, belongs to Pr3, about 1050–1080. No pagan stone is younger than that. It was just in that time that the cross was spreading: Christian markers are found on 55 % of the stones in RAK and on 75 % in Fp.

Six stones are not enough for firm statistics, and we want to be honest about it. The two earliest style groups hold 40 % of all dated stones. Four out of five in them would therefore happen by chance in about 9 cases in 100. That no pagan stone is younger than Pr3, although 30 % of the dated stones are, would happen by chance in about 17 cases in 100. The pattern points to the breakthrough of the conversion, but it cannot carry a conclusion on its own.

A land in the middle of a change of faith

In the first half of the eleventh century Sweden was on its way to becoming Christian, but was not yet. Olof Skötkonung, the first Swedish king we know was baptised, had coins struck at Sigtuna around the year 1000, some with crosses after English models. Västergötland got a bishop at Skara in the first half of the eleventh century. But around 1075 Adam of Bremen describes a great pagan temple at Uppsala, with images of Thor, Odin and Freyr. Thor, he writes, sat in the middle as the mightiest. According to later stories, King Ingi the Elder was driven out for a time because he refused to sacrifice. The conversion went family by family and district by district, over several generations, and the old gods lived on for a long time beside the new one. In that world a runestone was a public statement of where the family stood.

Where do they stand?

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The six stones are spread over five provinces, with Södermanland as the centre of gravity: three of six, although Södermanland has 17 % of the runestones with a legible text. That would happen by chance in about 6 cases in 100 – a hint, not a firm pattern. None stands in eastern Uppland, where the runestones are densest.

The most important question is which stones stood around them. If the pagan stones were remnants of districts that Christianity had not yet reached, their neighbours should have been pagan or silent. That was not so. Among the neighbouring stones within 25 kilometres, from the time up to about 1080, 74 % bear a cross or a Christian prayer – against 70 % around other stones from the same time. (Velanda has too few neighbours to be counted.) A difference this small easily arises by chance, but it points that way: the pagan stones stand among the Christian ones.

The old still shows in the landscape, though not in the words. 66 % of the runestones stand within 500 metres of a grave field, mostly from the Iron Age, against 24 % of random places in the same districts. That holds for the Christian stones too: they stand by the grave fields at least as often as the others. Only the bridge stones, raised where the road needed a bridge, stand clearly less often there. Christianity changed the stone's words but not its place.

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Did the pagan stones disappear?

Perhaps there were more, which have been lost? Rundata knows 415 Swedish runestones that have disappeared since they were described. Many were drawn by the antiquarians of the seventeenth century before they were blasted, built into walls or broken up. For 182 of them the text is known.

None of them has a pagan marker. Had the lost stones been pagan as often as the surviving ones – six of 1,111 – we would have expected a single one. So the zero says little on its own, but it sets a limit: the share of pagan stones among the lost ones is probably below 2 %. And the lost stones were as Christian as the surviving ones: 66 against 69 % bear a cross or a prayer. With style group and province held constant the odds ratio is 1.1, probably between 0.6 and 2.0 – in practice no difference (p 0.71). The stones lost since the seventeenth century were not different. If pagan stones were destroyed, it happened earlier, and that we cannot see.

Traces of iconoclasm?

Iconoclasm – deliberately destroying the images and signs of another faith – is a reasonable thought. In the Middle Ages Christian builders built runestones into the walls and foundations of churches. If they chose the pagan or non-Christian stones on purpose, the stones built in should more often lack a cross and a prayer.

Rundata's notes mention 26 dated stones that have been built into churches. Half of them bear a cross or a prayer themselves (50 %), against 62 % of the other stones. Among the stones whose text is so well preserved that a cross and a prayer could have been seen, the difference is 56 against 71 %. That points weakly towards iconoclasm, but a difference this large would arise by chance in about 16 cases in 100 (odds ratio 0.46, probably between 0.16 and 1.34). And the most important point speaks against it: half of the stones built in were Christian themselves. The builders took stone where stone was to be had.

Nor have the pagan images that survive been cut away. Thor's hammer at Stenkvista and Thor's fishing at Altuna can still be seen today.

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A tenable hypothesis of iconoclasm must therefore be narrower: that the images of the old gods in particular were sometimes removed, or turned inwards when the stone was built into a wall. It can be tested, but not with Rundata's records.

Why so few? Our hypothesis

That pagan signs are rare on the runestones is known, as are the Danish stones that ask Thor to hallow the runes or the monument. It has also been suggested that the Thor's hammer pendants, which become common in the Viking Age, were an answer to the cross. What we add is the measurement: when the pagan stones were carved compared with the Christian ones, which stones stood around them, and that neither the lost nor the built-in stones suggest there were more.

Our hypothesis is that Thor came to the runestones as an answer to the cross. The old faith had no tradition of writing its gods on stone. On the earliest stones, in RAK, 44 % lack any religious marker, and only one has Thor's name. It was the cross and the prayer that made the runestone a place of faith. When some answered all the same, they did so with the cross's own means – a symbol where the cross used to stand, a prayer at the end of the text – and only during the generation when the question was open. That is why they are so few.

A first test: Sweden and Denmark

If Thor was an answer to the cross, the Thor stones should turn up where and when Christianity came – not before, and not in districts it had not yet reached. In Sweden that holds: they belong to the time when the cross was spreading, and they stand among Christian stones.

Denmark offers a second test. There Christianity came earlier: on the Jelling stone, raised about 965, Harald Bluetooth says that he made the Danes Christian. Rundata knows three Danish stones that ask Thor to hallow the runes or the monument – at Glavendrup, Sønder Kirkeby and Virring – and one with a Thor's hammer, at Spentrup. All four have the oldest style, RAK. The dating of the Danish stones is uncertain, but the style suggests that there too Thor belongs to the time before and around the conversion.

So we state the hypothesis more sharply:

Thor was given a name on the runestones only where the cross already was, and only during the generation when the cross was new. He was an answer, not a survival.

The test has its limits: the Swedish stones are six and the Danish four, the datings are rough, and the difference in the neighbourhood is too small to be certain.

How the hypothesis can be tested further

1. The pendants. Thor's hammer pendants and cross pendants are found in graves and hoards. If the hammer was an answer to the cross, the pendants should be most common where and when the crosses came.
2. Denmark and Norway. A finer dating of the Danish Thor stones, and a comparison with Norway, can show whether Thor always appears in the generation of the conversion.
3. The families. If the pagan stones were an answer in a local struggle, the families behind them may have been neighbours or kin of those who raised Christian stones. The names on the stones can be tested in Vitki's network analysis.
4. The built-in stones. A survey of how the stones sat in the church walls – which side was turned outwards – can test the narrower hypothesis of iconoclasm.

Caveats

• Six stones are not enough for statistics. The probabilities above are exact, but they rest on very few cases.
• Our search rests on Rundata's text, translation and notes and can miss images not described there. A stone without Christian markers is not thereby pagan.
• The Rök stone is counted here in the earliest style group but is probably older, from the ninth century.
• The lost stones are only those described before they disappeared. Stones destroyed in the Middle Ages, before anyone wrote them down, do not show at all.
• The records of built-in stones come from Rundata's free notes and are not complete.
• The grave fields in the register are mostly undated, and the register is unevenly complete in different districts.
• An association is not a cause. The hypothesis explains the pattern, but other explanations are possible – for example that the pagan simply did not belong on a memorial stone, before and after the conversion.

See for yourself

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On how the prayer left the stones: The prayer fell silent – but the cross remained.

The maps, curves and models come from Vitki, an open tool for runestone research that you can download and run on your own computer from GitHub. The method is described in METHODS.md.

Sources and data

• Scandinavian Runic-text Data Base (Rundata), Department of Scandinavian Languages, Uppsala University. Open Database License.
• Register of ancient monuments (Kulturmiljöregistret), Swedish National Heritage Board (via K-samsök). Open data.
• Adam of Bremen. History of the Archbishops of Hamburg-Bremen. Transl. F. J. Tschan. New York: Columbia University Press, 1959 (Swedish translation by E. Svenberg, Stockholm: Proprius, 1984).
• Gräslund, A.-S. 2006. Dating the Swedish Viking-Age rune stones on stylistic grounds. In: M. Stoklund et al. (eds), Runes and their Secrets: Studies in Runology. Copenhagen: Museum Tusculanum Press, pp. 117–139.
• Sawyer, B. 2000. The Viking-Age Rune-Stones: Custom and Commemoration in Early Medieval Scandinavia. Oxford: Oxford University Press.
• Zachrisson, T. 1998. Gård, gräns, gravfält. Sammanhang kring ädelmetalldepåer och runstenar från vikingatid och tidigmedeltid i Uppland och Gästrikland. Stockholm Studies in Archaeology 15. Stockholm: Stockholm University.
• Photos: Wikimedia Commons, with photographer and licence in the captions. Figures: Vitki's corpus analysis in R.