Carving is almost the wrong word for what was done to them. The maker worked with the branch rather than against it, taking a forked oak limb and letting the natural split serve as the legs, then shaping a head, a torso, and the sockets where arms would be pegged in. Where the effort went is telling. The two are sharply differentiated: the woman wears her hair in a topknot, the man has short hair with a fringe, her breasts are set in as separate pieces, and his genitals were struck off at some point in the long time since.

They are the largest figures of their kind found in Germany, and they belong to a much wider habit. Anthropomorphic wooden figures turn up across northern Europe from Schleswig-Holstein to Norrland in Sweden, from the Neolithic through to the Middle Ages, though most cluster in the Iron Age and the Roman period. The Braak pair sit near the beginning of that concentration.

What makes Braak more than a pair of good carvings is what lay around them. The figures came out of the bog beside a pile of stones containing potsherds and clear evidence of burning, and fires had been built at the spot repeatedly, over time. That is the whole of the context. No structure, no bodies, no buried hoard — and archaeologists have been reasoning from it ever since.

It is not much, but it is suggestive. A bog is not somewhere you carry a three-metre oak figure by accident, and returning to the same waterlogged ground to burn something, again and again, is not accident either. Northern European bogs have given up weapons, cauldrons, food, jewellery and human bodies, all of it put there on purpose. The Braak figures were placed. The argument is over who they were placed for.

Fokke Sierksma weighed the find circumstances, the size of the figures and the deliberate pairing of a male with a female, and concluded it was near enough certain that they represent deities of northern Germanic peoples — that these communities located the residence of their gods in peat bogs, and understood the sacred union of a fertility god and goddess as the precondition for life continuing in all its forms.

Hilda Ellis Davidson proposed something more specific: a Lord and Lady of the Vanir, the Norse fertility gods, and wondered whether a memory of figures like these survives in the myth of Ask and Embla, the first man and woman, made from trees. Malcolm Todd was more cautious. The significance of bog figures, he wrote, is difficult to determine, but they should be related to the supra-mundane and perhaps specifically to presiding deities of fertility and war. And a plainer reading has never gone away: that the pair are not gods at all, but ancestors.

The figures are held by the Schleswig-Holstein state archaeological museum at Gottorf Castle, which dates them earlier than the radiocarbon results do. The carbon puts them in the third or second century BCE; the museum reaches back as far as 400. That is not the only uncertainty attached to what a visitor actually sees.

Karl Schlabow, the museum's post-war conservator, has been accused of over-restoring the objects in his care, and specifically of accentuating the sexual characteristics of the Braak figures. It is a genuinely awkward problem, because the readings that carry the most weight — the fertility pair, the Lord and Lady of the Vanir — rest partly on how emphatically the two bodies are sexed, and the hand that made them emphatic may have been a twentieth-century one. The oak is Iron Age. How much of the meaning is, nobody can now say. The open mouths, at least, appear to be original, and they remain the strangest thing about the pair: two figures shouting into a bog, for two thousand years, at no one.