Iron coin die of William I
England, AD 1066-87
A die used to strike coins for William the Conqueror
Medieval coins were struck by hand, normally using a hammer and a pair of dies. These pressed the design into the surfaces of the blank coin. Dies from the early Middle Ages are rarely found for a number of reasons: they were sometimes re-used, becoming shorter each time a new design was cut into the face; they were probably also sometimes destroyed after use, to prevent them from falling into the hands of forgers; dies were made of iron, and iron corrodes very easily; some dies may have been found but not recognized, simply because of their condition.
Four dies did turn up as a result of rescue excavations along the London waterfront in the 1980s. Archaeologists were allowed in for a brief period of excavation before building development. Because there was only a short time allowed, the dies were not found during the excavation itself. It was only when metal detectorists went over the spoil heaps (the piles of earth from the excavation) that the four dies were found. This one is an upper die (trussel) of William I (reigned 1066-87). The inscription shows that it was used to strike coins in the name of the moneyer Ethelric of Wareham.
M.M. Archibald, J.R.S. Lang and G. Milne, 'Four Early Medieval coin dies from the London waterfront', Numismatic Chronicle-10, 155 (1995), pp. 163-200