Trust and scarcity: from hacksilver to on-chain

Every money has to settle three things: whether a payment is genuine, who keeps track of who owns what, and what stops anyone making more of it. Modern payment systems answer with banks, card networks and central banks. Public blockchains answer with open software, shared records and rules written into code. A Viking trader at Kaupang or Birka in the 9th century answered with a lump of silver, a folding balance and a sharp knife.

This series follows those answers through the hoards. It is a history first. Where we draw parallels with modern digital money, they are analogies, each with a note on where it breaks. Nobody in the Viking age anticipated cryptocurrency, and the point of the comparison is to see both systems more clearly, not to flatter either.

In the bullion economy no authority stood behind the metal. Silver was worth what it weighed, and it was paid by cutting and weighing (the bullion economy). From the 860s and 870s standard weights spread across most of Scandinavia, so that strangers could agree on a mass (folding balances). The knife checked what the scale could not: nicks exposed plated fakes and let a payee feel whether an alloy was too hard or too soft (nicks and pecks).

Trust did not vanish; it moved to the tools and the people holding them. The owner of the copper balance box found in Sigtuna in 1911 had runes cut round it naming him, Djarfr, recording where he got the scales and picturing a raven tearing apart a thief. A balance was a merchant's most valuable possession because it was how everyone else decided whether to trust him.

Coins offered a short cut. Instead of testing each piece, you accepted the issuer's stamp. Viking rulers in York and East Anglia were striking their own pennies by the mid-890s, yet in the Danelaw bullion and coin ran side by side from about 865 until at least 930-940. Kershaw finds local coins only occasionally tested there, while foreign dirhams were always cut: people trusted what they knew.

Edgar's reform of about 973 made the short cut national: one design from some forty mints, silver of high and uniform fineness, and a law that one coinage should run throughout the kingdom. In Scandinavia, Sweyn Forkbeard and Olof Skötkonung struck the first royal coins around 995. The scales went back in their boxes at different speeds: by about 1030 in Ireland, by the 1060s in the Scottish isles, and on Gotland only after the island began striking its own coins about 1140 (from weight to coin).

The Viking age left no account books, but it left hoards. The Cuerdale hoard lists, in metal, its owner's sources: about 5,000 Danelaw coins, 1,000 English, 1,000 Frankish, some 50 Islamic, and more than 36 kg of bullion. The Vale of York hoard can be dated to about 928 from the freshness of King Athelstan's coins (hoards as ledgers).

Modern science adds provenance. Inscriptions name mints and years; die links tie coins to workshops; lead isotopes traced the Galloway hoard's lidded vessel to Iranian ore and showed that most of its hacksilver was melted English coin (tracing provenance).

Silver's scarcity was physical and, for Scandinavians, distant. Much of it came from Central Asian mines by way of Samanid mints and the Volga trade, a trade bound up with the sale of enslaved people (dirhams north). Gotland alone has yielded about 168,000 Viking-age silver coins. When the eastern supply dried up at the end of the 10th century, Scandinavia's money changed with it, as western and then royal coin took over.

Within that scarcity people made change by cutting: dirham fragments found as single finds in England average only 0.57 g. Once kings controlled the coin, they also decided what counted as good money, and how much of it there was.

Set out plainly, here are the comparisons this series draws. Each is an analogy, not a claim of descent.