Charlemagne's Black Stones: The Re-Use of Roman Columns in Early Medieval Europe
Peacock, D. P. S., Antiquity
One of the most important documents bearing on Carolingian trade is a letter written by Charlemagne to King Offa of Mercia, apparently shortly after the death of Pope Hadrian I in AD 796. He discusses the problem of merchants fraudulently posing as pilgrims to avoid paying tolls and stresses the need to give traders the support of the law. He then goes on to reply to a request made by Offa in previous correspondence (in Whitelock's translation (1955: 782)):
As for the black stones which your Reverence begged to be sent to you, let a messenger come and consider what kind you have in mind, and we will willingly order for them to be given, wherever they are to be found, and will help with their transport. But as you have intimated your wishes concerning the length of the stones, so our people make a demand about the size of cloaks, that you may order them to be such as used to come to us in former times.
For many years scholars have debated the nature of the black stones. Rahtz (1981: 4) and more recently Hodges (1982: 124; 1989: 136) have plausibly suggested that they were Mayen mill stones. There is much to be said for this: Mayen lava is dark enough to be called black, the quarries are a little over 100 km from Charlemagne's capital in Aachen, and fragments of querns from this source are found in some quantity on many Pre-Conquest sites in England (cf. Hinton 1990: 129). Yet would a king concern himself with something as basic as a humble quern? Offa intimates the 'length' of the stones, but querns would be quantified by number or diameter, not length. As if to emphasize length, Charlemagne adds a grouse about the size of English cloaks, which other documents indicate he found inadequate for defending himself against wind and rain when riding and too short to cover himself up in bed (Loyn 1962: 85). Reference to the length of the stones, and a hint of special arrangements for their transport, points to an exceptionally heavy item and it is difficult to imagine a long, heavy stone artefact other than a column. Furthermore, mention of special transport suggests that they were not a regular item of trade to be entrusted to the merchants, but more probably a gift.
An alternative suggestion is that the statues were of a black marble such as that from Tournai (Dodwell 1982: 35; Rahtz & Meeson 1992: 73). Tournai marble was fashioned into small columns as well as the better-known fonts which were distributed to Britain and occur in greater numbers on the Continent within about 150-km radius of the quarry (Dunning 1944). Here the main problem is chronological: it seems probable that Tournai marble was introduced into Britain during the 12th century, perhaps by Henry de Blois, Bishop of Winchester, an innovation that led to the exploitation of Purbeck marble, which is black rather than grey when polished with grease (Biddle 1965: 260; Blair 1991: 41). The earliest evidence for the possible use of black marble is a reference to the Waltham crucifix, of the early 11th century, said to be of 'black flint' impenetrable to nails. Although hardness is an established geological parameter, the test is not helpful as a means of identification in this case as on one occasion it produced a flow of blood (Dodwell 1982: 35). Furthermore, the chronological problem remains.
Of course, black marbles are not limited to the Tournai region; at one time Belgian black, from quarries in central Belgium, was regarded as the finest anywhere in the world (Lee 1888: 45). However, there is no evidence that this material was worked before the 19th century, and Charlemagne's biographer, Einhard the Frank, specifically states that he was unable to obtain marble and columns locally. As he was a contemporary of Charlemagne his account may well be reliable (see e.g. Firchow & Zeydel (1972: 95), for a translation of Einhard's Vita Karoli Magni).
Charlemagne seems to have used prodigious quantities of columns in his building enterprises. …