One can hardly think of Rome without picturing the massive dome of St. Peter’s. Clearly symbolic of Catholicism and, more subtly, of the transition from late pagan antiquity to the ascendancy of Christianity, the basilica has a rich and varied history. As Lex Bosman states in the introduction to The Power of Tradition, “The church of St. Peter’s in the Vatican is not special only because of its size and its splendor. It is also, more than any other building in Western Europe, a testimony to part of the history of Christianity in different types of stone” (9).

The St. Peter’s we see today is the new basilica that in the sixteenth and seventeenth centuries replaced the fourth-century structure commissioned by the Emperor Constantine. Located on land once used for a Roman circus, Constantine’s basilica stood over the grave of the apostle Peter for more than 1,000 years until its replacement by the massive later structure.

While Bosman’s focus is on the use of spolia in both basilicas, he also explores the complicated topic of spolia in general. This topic is the subject of a number of studies, such as The Eloquence of Appropriation: Prolegomena to an Understanding of Spolia in Early Christian Rome by Maria Fabricius Hansen (Rome: Analecta Romana Instituti Danici, Supplementum 33, 2003). Bosman’s work encourages readers to consider questions pertaining to the reuse of old materials, be it for symbolic, economic, or decorative reasons.

In his introduction, he refers to the range of scholarship that deals with the designs for and construction of the new St. Peter’s. This is a complex topic, considering the succession of architects, patrons, and changing concepts of the new structure. Older sources such as Vasari as well as surviving documents and plans have led to various scholarly approaches to the study of the later basilica and of the transition from early to later structure. Studies of the plans of the architects who played a role in the design of the “new” basilica abound; Bramante, Raphael, Giuliano da Sangallo, Michelangelo, Maderno, and others were each instrumental in the transformation from the Constantinian to the new basilica. Also crucial to the ultimate form of the new St. Peter’s are the patron popes, including Nicolas V and Julius II. Throughout, Bosman clarifies the significance of continuity in the process of transition from old to new basilica; the fact that the Constantinian structure was built over the grave of St. Peter, a major early Christian site, has been crucial to the form and decoration of the new.

In posing the question of the use of spolia, Bosman notes that in general there may have been several intents: to reference the past, for instance, or—on a more mundane level—to be economically astute, recycling rather than beginning anew. Much of his discussion focuses on this issue.

Following the introductory material, Bosman’s book is divided into four chapters: “The Fourth Century,” “Towards the New St. Peter’s,” “Bramante’s Tegurium and Spolia in Sixteenth-century Architecture,” and “The Realisation of New St. Peter’s.” Each is informative and detailed, and each includes supportive diagrams, plans, and illustrations. The lengths of the chapters indicate the author’s focus: the first two are thirty-seven and forty-seven pages long while the last two are thirteen and nineteen pages in length.

In the first chapter, Bosman discusses the two important Christian basilicas built by Constantine. While St. Peter’s was “a church of unsurpassed dimensions and decoration . . . built to house the tomb of Peter” (19), the second, also impressive in size and appearance, was intended for the bishop of Rome. The Basilica Salvatoris (which would become known as S. Giovanni in Laterano) was constructed after Constantine’s victory over Maxentius. Constantine built the two basilicas outside the city center in part, it seems, to avoid alienation from non-Christians. The Basilica Salvatoris was constructed in southeastern Rome, on the site of the razed barracks of the Equites Singulares, thus erasing the memory of Maxentius, while that of St. Peter, marking the grave of the saint, was outside the walls to the west.

Bosman discusses the plan and rationale for the fourth-century basilica of St. Peter, paying particular attention to what he deems the most significant architectural element, the columns. The nave and side aisles were divided by four arcades, each composed of twenty-two monolithic columns, and the total count of columns was one hundred. He questions the importance of the use of mixed materials, since the forty-four columns placed between the nave and inner aisles were of varying stones, resulting in a lack of uniformity.

Our understanding of the fourth-century columns comes in great part from drawings of sixteenth-century architects and other references to materials and dimensions. Bosman details the type of material (from granito bianco and rossetto to cipolla), citing some difficulties of interpretation of the sources. He reports that the general scholarly opinion has been that these columns were indeed spolia, in part because older texts suggest this. Vasari, for instance, agrees with the consensus that the columns were taken from Hadrian’s Mausoleum, adding that their age provided enhancement for the newer structure. Yet other evidence suggests that some of the columns were new. Bosman’s view is that a substantial number of bases and shafts were of new material rather than reused, and that both new and recycled materials were thus incorporated.

He discusses this topic in depth, referring to the Arch of Constantine—on which the sculptural reliefs reused from older Roman monuments had indeed been incorporated because of their reference to the past—and concludes that the richly colored columns, both new and spolia, were placed by “careful and deliberate choice and design” (56). He argues, however, that in this case material, not embedded reference, was of the greatest importance.

In chapter 2, Bosman gives a detailed account of the various stages of planning for and construction of the new basilica, referring to such architectural giants as Donato Bramante who, Bosman argues, had intended to incorporate parts of the fourth-century basilica into the new. Later plans eliminated this possibility; and in the early seventeenth century, the complete demolition of the Constantinian basilica became a reality. Throughout, Bosman attempts to clarify the confusion that derives from numerous plans as well as the complicated relationships among the architects and patrons.

The process of designing and building the new St. Peter’s led to decisions about the incorporation of spolia from the old structure. Bosman draws attention to Bramante’s drawings that reference continuity between old and new basilicas by joining parts of both structures and by use of spolia in the new. He concludes the chapter with discussion of the addition of spolia from structures other than the old basilica: the “established practice” of using spolia in the new St. Peter’s “which made Michelangelo continue to use [old architectural elements], be it largely with material not originating from the old basilica and therefore also no longer imbued with the idea to visualize the tradition of the early Christian basilica” (104).

In chapter 3, Bosman considers Bramante’s Tegurium, an architectural element that seems to have resembled a Roman triumphal arch but that did not stand alone because its side walls were connected to the fourth-century apse. The Tegurium, demolished by 1592, is known to us mainly through illustrations. Its function has been understood as protective, a shield for the pope from the elements, and its state was considered temporary.

Although in a sense this chapter seems to be a digression, Bosman includes it as part of his consideration of spolia, questioning the Tegurium’s function and examining it in conjunction with comparative structures, such as Bramante’s Tempietto, in which the architect did incorporate spolia. Bosman asserts that the Tegurium had been planned as a replacement for the former ornament around the altar of the fourth-century basilica and that there is no conclusive evidence Bramante used spolia in this structure as he had in others.

In the fourth and final chapter Bosman focuses on the new St. Peter’s basilica, continuing his detailed account of architects and designs. He considers the accusation that Michelangelo slandered Bramante: “spreading the idea that Donato Bramante neglected the old, classical remains by carelessly pulling down the columns and letting them fall to pieces” (123). Bosman counters with his assertion that there seems to be sufficient evidence that Bramante and those who followed him “treated the columns of the old basilica with respect and care so they could be used again in the new structure” (123–24). Only a few columns are no longer extant, and others are unbroken, facts that suggest not demolition but careful removal in order that they could be used in the construction of the new basilica.

Bosman refers specifically to a pair of africano columns which he maintains were deliberately chosen for the narthex “to embody the meaning of the presence of the old basilica“ (136). The two “precious columns” have been described by Pompeo Ugonio as “sustain[ing] the church like the apostles Peter and Paul had once done” (136). Their incorporation in the new basilica, then, was an expression of the continuity between the two structures.

In the book’s conclusion, Bosman maintains that despite much research on the Constantinian basilica of St. Peter’s the importance of the materials used has been considered infrequently. Contrary to scholarly opinion, he asserts that not all columns used in the fourth-century St. Peter’s were spolia. The columns used in both Constantinian structures were chosen with care, but whether they were spolia or new was inconsequential: it was the material, not the age or prior use of the columns, that was of greatest import. Neither the necessities of economic decline nor the historical significance embedded in spolia played a major role. The material itself and the richness and color of the various stones were of crucial import.

The reuse of older materials is interpreted differently for the later St. Peter’s basilica, however. Bosman maintains that there is no definitive evidence that Bramante (or Julius) planned to replace the earlier church completely, arguing that “to entirely replace the most venerable church of St. Peter’s, originally built at the initiative of the first Christian emperor Constantine, would seem to be a revolutionary act indeed” (18). He suggests that there was originally a desire to incorporate some of the older basilica into the design of the new and that ultimately the use of spolia, columns from the fourth-century structure, would “offer a way out of the dilemma” (143). The complete replacement of the old basilica with the new, Bosman maintains, had not been planned. Rather it resulted from the tedious process of planning and constructing. “The use of spolia proved to be an almost necessary element in this process, since it made possible the demolition of the most important sanctuary in Christianity in Europe [while it] preserve[d] the essence of the old structure after the building itself had disappeared” (152). He suggests that spolia columns were not incorporated simply because they were available, “but because they could show a necessary part of the history of St Peter’s which would otherwise have been lost” (152).

In sum, then, spolia were used for different reasons in the two St. Peter’s basilicas. In the earlier structure spolia were chosen “because of the richness of the colourful kinds of marble and granite, not because they were spolia; in the sixteenth and seventeenth century spolia from the early Christian basilica were reused in new St. Peter’s as relics of the old church to guarantee the continuity and the history of this building” (152).

Bosman presents complex issues in his thorough, detailed treatise. His approach to his specific topic sheds new light on, and raises further questions about, the use of such materials in general. His employment of comparative material throughout The Power of Tradition enhances its arguments. The richness of the topic is equaled by the wealth of material he references.

Although his argument is presented in great detail, and with some repetition, Bosman arrives at bold conclusions. In each chapter there are clear diagrams, informative historical plans, and photographs, a number of them in color. Particularly helpful is one on page 37 that illustrates the type and color of the columns of the Constantinian basilica. Repeated and enlarged, this colorful diagram makes handsome endpapers.

The bibliography is extensive and particularly helpful with references to pre- and post-1700 sources. The appendices on the popes and their architects and on the concordance of columns are clear and useful. The index is short but helpful.

This book is intended for scholars and graduate students. The price is reasonable, and it will undoubtedly be a part of private collections as well as those of academic libraries. Despite some tediousness, Bosman should be applauded for his cogent arguments and significant findings.