In Turkey and North Africa, and in spite of the encroachment of increasingly city-dwelling populations, fortifications built and decorated with antique spolia survive in great numbers, built by Byzantines, Armenians, Seljuks and later Turks, Arabs, Crusaders Christian and Moslem  and, eventually, by the French in Algeria. They allow us to chart aesthetic as well as practical use of earlier monuments, sometimes on or near the same site, sometimes brought from afar. The enormous work required to handle often immense blocks, and the profuse use of decoration, give the lie to the old idea that such structures were a hasty reaction to imminent trouble. Rather, although couched in what to post-Renaissance eyes may seem a shaky and haphazard manner, often crude and with inscriptions sometimes inverted, these walls impressed contemporaries and successors alike, sustaining the antique notion of the importance of city and fortress walls as a potent symbol of identity and continuing power.


Undoubtedly, the profusely surviving earlier fortresses and city walls acted as exemplars, so that we find several enthusiastic redeployments of the classical tradition: the use of Hellenistic-inspired bossed masonry and multicoloured courses by the Byzantines, and at the time of the Crusades; antique bas-reliefs and sculptures, especially lions, to decorate walls and gates; a taste in several Anatolian city walls for some imitation of Constantinople's Golden Gate; a long-lived enthusiasm for the use for marble columns as both structural and decorative elements in such walls; and a revival of monumental inscriptions. Such enthusiasms were shared by Christians and Muslims alike, even to the acceptance by the Seljuks of iconic sculpture implying (like their re-invention of monumental inscriptions) an admiration for the antique.


Why did the interest in such uses of spolia decline from what was, in this respect, the golden age of the earlier Middle Ages? Partly, at least because, after the Crusades (when travel had decidedly broadened the mind), access to Turkey and North Africa became difficult except for traders (who were not interested in antiquities) and ambassadors (who wished only to collect museum-quality pieces). The Western military eye, as it were, was missing for centuries: the Knights were pushed from Bodrum to Rhodes, and then to Malta; there was no new Turkish tradition of fortress-building (they tended to continue using existing structures); and Western military interest in Turkey (which, through essential surveys, gives us much background information about fortifications and weaponry) begins only in the 18th century, and declines during the 19th  century. The antiquarian discovery of Turkey likewise begins only in the later 18th century but, even then, spolia had no place unless they were of exceptional beauty. This is seen in the highly selective plundering by Westerners of Eastern sites such as Delos or Leptis, which was done for prize pieces of special marble or granite, rather than for the wholesale extraction of building materials, which was the purlieu of North Africans and Turks, who continued to rob antique sites wholesale, turning columns into cannon balls and bas-reliefs into tombstones, and carting away whole cities over large distances for use in buildings, roads and eventually railways.


Another reason for a declining interest in such use of spolia is because Renaissance-inspired aesthetics in the West saw buildings as unitary, and not to be assembled from diverse pieces; again, spolia were scarce in the West, so that there is no extravaganza to match the rare example of the decoration with spolia of the fort at Narbonne in the 17th century. Most importantly fortification, with gunpowder artillery, became a developing science, and new forms were needed, often on an immense scale, which could not for that reason employ spolia. Hence after the Crusades, spolia enceintes were no longer built, except for Charles V's fort at La Goulette (Carthage / Tunis), and in French Algeria. Gunpowder (often by naval bombardment) was also responsible for the destruction of several North African enceintes, meaning that spolia in the coastal regions - the walls of Algiers, the Tunis forts, Bougie or Oran - were often pounded to dust.


Finally, the great and increasing vogue for marble in the West paradoxically saved spolia, if only from Westerners. Thus by the end of the 17th century the thirst for marble in Europe was so great that spolia could not satisfy it in terms of quantity, quality, the enormous transport costs over great distances (plus expensive rigging, deadlegs and lifting devices, and specially strengthened ships), or the work required for recutting - hence the enormously expensive quarries opened up by Louis XIV and his successors in Languedoc and the Pyrenees to staunch the crippling costs of imports from Carrara. Spolia were still imported into France throughout the eighteenth century, but as trophies and treasures of especially prized marbles and porphyries, not as building stone. Inventories of French Royal marble stocks survive in quantity, and tallies were kept to the nearest cubic inch - but these were for marbles for cutting up, whereas spolia statues and bas-reliefs went to the Royal collections.


The French invasion of Algeria provided close contact with spolia in profusion, and we may draw three general conclusions from their relationship with Roman ruins which might inform us about the complexion and extraordinary inventiveness of mediaeval re-use. The first is is that the rate of destruction is relative to the march of civilization: for all their re-use of them at the start, the French did indeed obliterate more antiquities in ten years than had the Arabs in two hundred. Transferring this mechanism to the mediaeval West, we can understand that it was the growth of towns that at first prized, and then destroyed antiquities, as the thirst for building stone became insatiable.


The second is the nature, speed and extent of the reuse. The French, for all the exertions of their Engineers, often experienced considerable difficulty in re-erecting Roman fortifications because of the size of the blocks involved, and their lack of manpower and machinery; so it is incorrect to see the erection of spolia walls in the Middle Ages as rushed jobs: rather, they should be seen as intellectual statements of civic pride and aesthetic integrity.


The third conclusion stems from the second: unlike the inventive Seljuks or the renovatio-minded Byzantines, the French never lavished any aesthetics on their fortifications, in spite of abundant materials.[1] Why not? Because, apart from changed aesthetic horizons, they were continually pressed for men, money and machinery - they always needed money to build hospitals, latrines, bakeries, or sewers. Above all, their whole fort-building strategy was soon influenced by changes in artillery and defence technology, including fears of a serious artillery-led attack by a European power, rather than by Arabs armed with rifles. This, aided by the growing popularity of concrete, and the need to update walls every few years to cope with developing artillery techniques, made spolia walls walls just as much useless antiques as the enormous marble-fed Turkish pierriers at the Dardanelles. Spolia, as an index of tradition and permanence, were out of place in such a fast-changing, modernistic setting. And out of fashion for all but the grand gesture, such as triumphal arches transplanted to Paris.


Thus the ideal of beautiful fortifications, which augment their moral firepower by their antique connections, and display columns, bas-reliefs, and squared and shiny  blocks, attenuates in the face of Renaissance notions of order and uniformity, and of the new construction strategies required by gunpowder. It vanishes completely with 19th century technology, leaving the earlier Middle Ages as the only period seriously to embellish their fortifications with spolia - and sometimes, as Matthew Paris has it, even cum altis turribus et propugnaculis et lapidibus quadris et incisis columpnis marmoreis decenter ornato[2].



[1] SHAT MR1317, item 3, DE RASIERES: Notice descriptive sur Philippeville et Stora au commencement de l'occupation française,  30 January 1839, p. 9: enough three-metre columns were unearthed on  the site of the Fort de France to make them believe that this was a fortified Capitol - but there was no suggestion of reusing the columns in what they built;

[2] MARSHALL, Warfare, cit., p. 103;