BMCR 2021.09.18

The Basilica of Saint John Lateran to 1600

, , , The Basilica of Saint John Lateran to 1600. British School at Rome studies. Cambridge; New York: Cambridge University Press, 2020. Pp. 608. ISBN 9781108839761 $140.00.

[Authors and titles are listed at the end of the review.]

This sizeable book is the publication of a conference hosted by the British School at Rome in 2016, which in turn emerged from the School’s Lateran Project, inaugurated in 2012 by Ian Haynes (Newcastle University), Paolo Liverani (University of Florence), Giandomenico Spinola (Vatican Museums), and Salvatore Piro (National Research Council of Italy). The Project set out to apply the latest non-invasive technology to a survey of the sprawling site under and around the cathedral of St. John Lateran, where traditional excavations had uncovered remains thought to belong to the urban villa of Plautius Lateranus confiscated by Nero in 65 CE; the castra nova of the imperial horse guards erected by Septimius Severus in 193-197; and the Constantinian foundations of the cathedral begun in 313. The technologies used included ground-penetrating radar, laser scanning, and eventually the construction of digital models by the “architectural visualizer” Iwan Peverett (New Visions Heritage). As the visualization moved above ground the team collaborated with Lex Bosman (University of Amsterdam), who contributed expertise on the standing basilica. Finally, the conference recruited leading lights in the fields of medieval and postmedieval Roman architecture, art, history, liturgy, and cult practices to share their research on the cathedral concurrently with reports on the Project.

The publication is entirely in English. Five chapters (2, 3, 5-7) deal with the pre-Christian phases of the site; ten (9-17, 19) treat the Constantinian basilica and its medieval alterations, liturgy, and historiography; four (18, 20-22) concern postmedieval developments; and two (4, 8) describe two of the technologies employed: ground-penetrating radar and digital visualization.

The book is not for beginners. Despite the arrangement of chapter topics in roughly chronological order, it is not meant to offer a consecutive overview of the archaeological area from antiquity to the seventeenth century. There is no general account of the site, and no ground plan that shows the multiple building phases simultaneously and with equal clarity (illustrations are many but specific and often too small). Some prior familiarity with the basilica and its history is assumed. Although the reader who stubbornly persists in attempting to extract a quasi-monographical account may be rewarded, it is easier and arguably more productive to take each chapter for what it offers on its own terms, which is usually quite a lot. Inevitably, the reader who takes this approach will be drawn to the chapters that most engage her own prior interests and expertise, but a medievalist can profitably read all of them.

The first seven chapters offer important topographical information and correctives to the basilica’s received prehistory. The site was once a sharply sloping hill that peaked under the later nave. The first-century villa accordingly was on two levels, higher under the nave and lower beneath the thirteenth-century apse and ambulatory. Krautheimer expressed the once-common view that the walls under the nave belonged to the egregiae Lateranorum aedes of Plautius Lateranus, which were thought to give the cathedral its toponym.[1] This is debunked by Liverani (ch. 2), who argues that the name derived from a later domus given by Septimius Severus to Titus Sextius Lateranus, which stood northeast of the basilica and later became the residence of the popes. Liverani identifies part of Sextius’s aedes Laterani in the late antique walls below the Sancta Sanctorum, and he doubts that this mansion had any connection with the much earlier villa of Plautius. Spinola, who provides a detailed reconstruction of the first-century villa and its multiple remodelings (ch. 5), takes a different view, maintaining that the home of Plautius covered such a vast area that the aedes later given to Sextius were part of it.

Much of the villa on the hill disappeared under the “New Fort” of the imperial horse guards erected by Septimius Severus. Haynes and Liverani (ch. 6) argue that this Castra Nova was the cornerstone of a planned “new east” of Rome, an area extending from the Lateran to Porta Maggiore dominated by imperial residences and military castra. Their reconstruction of the fort (Fig. 6.4) shows a towered rectangular wall enclosing densely packed “barrack-like” buildings and a lavishly decorated headquarters (principia). It stood on a platform created by brick and concrete substructures that leveled the hill. Some of its marble ornament may have been recycled from the villa. Noting that the fort was too small to accommodate a full unit of cavalry, the authors propose that some of the troops were quartered elsewhere, guarding the Sessorian palace and points eastward. The Castra Nova was a showpiece, announcing Severus’s “vision of power and governance” (p. 109). It remained in use, and essentially unchanged, until it was abandoned in 312 and razed to build the enormous Constantinian basilica on its platform (Fig. 6.7). The church rose directly over the principia, along the central axis of the Castra although not precisely aligned with it. Again, materials stripped from the old building were reused. Some of the ornaments of the villa may have found a third life.

Enough of the Constantinian basilica survives to reconstruct the outlines of its plan and elevation with some conviction, and it is familiar to specialists and their students through axonometric reconstructions published by Krautheimer, Sible De Blaauw, and Hugo Brandenburg.[2] Many uncertainties remain, however, notably the elevation of the nave colonnades, the roofing, and the form of the fastigium, described in the Liber pontificalis as a silver-clad structure with 13 five-foot-tall statues on the side toward the nave and five five-foot-tall statues facing the apse.[3] Confronting the uncertainties, the Lateran Project went beyond all previous efforts to reconstruct the basilica with the creation of a digital 3-D model built from data generated by laser scanning, photogrammetry, ortho-rectified photography, and ground-penetrating radar, integrated with verbal and visual information from traditional historic sources. The construction of the model, its methods and guiding philosophy are described in ch. 8. The team was guided by the London Charter for the Computer-Based Visualization of Cultural Heritage of 2009. The authors are clear that the accuracy of computer-generated models is necessarily contingent on the data supplied, and the model is repeatedly termed a “provocation” to further research. On the basis of their experience with the Lateran, they urge that an “architecturally trained illustrator or visualiser” (p. 145) must be part of any such project from the outset, not brought in at the end to depict what word-based investigators have imagined.

After this long and thoughtful introduction, it is disappointing that the book contains only two still images from the rendered model (i.e., the model with colors, textures, and lighting; Figs. 8.8, 9.7). Bosman is the only author to make use of it (ch. 9). His concern is the column shafts. He confirms the presence of 42 shafts of verde antico in the colonnades between the outer and inner aisles and reconstructs 38 shafts of red granite along the nave. Against previous opinion, he argues that the nave shafts, although spolia, were uniform in height as well as material, and he speculates that both sets of shafts came from “stockpiles,” a recent topos of spolia studies in Rome. Bosman’s most original argument pertains to the two fine fluted shafts of giallo antico currently in the transept. Observing that they are identical in size to the giallo anticoshafts on the Arch of Constantine, he argues that they came “from the same stock” (p. 185), i.e., they are original to the Constantinian basilica. Extrapolating a second pair, he finds place for four columns at the ends of the aisle colonnades (Figs. 9.12, 9.13), delimiting the mysterious “aisle transepts” discovered by Krautheimer.

All of Bosman’s conclusions are incorporated in the model, along with uniform Ionic capitals in the nave colonnades. The latter are a striking novelty, for which the only evidence is an anonymous description of the basilica as it was before Borromini’s remodeling, when most of the columns were enclosed in brick piers.[4] While almost sure to be controversial, the Ionic elevation does find indirect support in the Ionic granite colonnades of S. Crisogono and other churches of the twelfth- and thirteenth-century Roman renovatio, for which the Lateran would have been an obvious model. More important from the team’s point of view was the reconstruction of the lighting (“a huge undertaking to get right,” p. 144), and the result is an invaluable “provocation.” The rendered model (Fig. 8.8) seems to show all of the lamps aglow in daylight; it would be interesting to see the effect at night, when many Christian liturgies took place.

The construction history continues with the Baptistery (ch. 11), the fountain complex of Pope Hilarus (an under-illustrated ch. 12), the ninth-century porch and thirteenth-century transept towers (ch. 13), and P. C. Claussen’s masterful analysis of Pope Nicholas IV’s new transept (ch. 16). A re-examination of the twelfth-century porch was occasioned by the remarkable discovery of 42 fragments of its frieze (regrettably shorn of mosaic) in a storage room of the Vatican Museums in 2009 (ch. 14). Two chapters offer critical analyses of fundamental sources: Rosamund McKitterick on the Liber pontificalis (ch. 10, a must-read for anyone thinking of using this “book” for documentary purposes) and John Romano on documents of the papal liturgy, specifically the rite of the reconciliation of penitents celebrated on Maundy Thursday (ch. 19). Romano would have done well to make reference to the digital model, as his reconstruction of the choreography of the ceremony, seemingly suited to a moderately scaled titular basilica, is almost impossible to imagine in the giant cathedral. He gives a compelling account of the history of the reconciliation ritual from the early middle ages to the thirteenth century, when it abruptly became a ritual of exclusion (excommunication) rather than reintegration.

Carola Jäggi’s overview of the rivalry between the cathedral and St. Peter’s, one the official seat of the pope and the other his de facto center of power, usefully situates the Lateran in the context of Roman ecclesiastical politics (ch. 15). Daniela Mondini’s study of the spectacular half-figure reliquaries of the skulls of St. Peter and St. Paul commissioned by Pope Urban V in 1369 also traces a kind of competition with St. Peter’s (ch. 17). Of the chapters treating the postmedieval history, I especially enjoyed Nadja Horsch’s account of the Passion relics invented around 1450, shortly after the popes abandoned the Lateran palace to reside at the Vatican (ch. 20). Suddenly, architectural components of the patriarchium, including three antique door frames and a marble stairway, came to be seen as remains of the palace of Pilate in Jerusalem; other objects were associated with the body of Christ. Informed by the latest scholarship on medieval devotional practices and mnemonics, Horsch’s chapter elucidates how the Lateran relics came about, how they were used by pilgrims, and how they eventually figured in the Christian imaginary throughout Europe. The discussion of “translocated topography” is a highlight.

With its wealth of new information and variety of perspectives, The Basilica of St. John Lateran is an exemplary multi-disciplinary publication and by far the most important contribution to the study of the Constantinian cathedral in nearly half a century. Kudos to the editors and all who supported their work.

Authors and titles

Ian P. Haynes, Paolo Liverani, and Lex Bosman, The Lateran Basilica to 1600, 1-5
Paolo Liverani, The Evolution of the Lateran: From the Domus to the Episcopal Complex, 6-24
Rossella Rea and Nicoletta Saviani, At the Foot of the Lateran Hill, from Via Sannio to Viale Ipponio: Archaeological Investigations Prior to the Construction of Metro Line C, 25-51
Salvatore Piro, Ian P. Haynes, Paolo Liverani, and Daniela Zamuner, Ground-Penetrating Radar Survey in the Saint John Lateran Basilica Complex, 52-70
Giandomenico Spinola, The First Residential Phases of the Lateran Area and a Hypothesis to Explain the So-Called Trapezoidal Building, 71-90
Ian P. Haynes and Paolo Liverani, The Castra Nova and the Severan Transformation of Rome, 91-113
Sabina Francini, Andrea Busiri Vici and the Excavation of 1876: A Reassessment of the Archaeological Evidence, 114-33
Lex Bosman, Paolo Liverani, Iwan Peverett, and Ian P. Haynes, Visualising the Constantinian Basilica, 134-67
Lex Bosman, Constantine’s Spolia: A Set of Columns for San Giovanni in Laterano and the Arch of Constantine in Rome, 168-96
Rosamond McKitterick, The Constantinian Basilica in the Early Medieval Liber Pontificalis, 197-220
Olof Brandt, The Lateran Baptistery in the Fourth and Fifth Centuries: New Certainties and Unresolved Questions, 221-38
Paolo Liverani and Ian P. Haynes, The Nymphaeum of Pope Hilarus, 239-49
Lia Barelli, Examples of Medieval Construction Techniques in the Basilica of San Giovanni in Laterano, 250-75
Anna Maria De Strobel and Nicoletta Bernacchio, The Medieval Portico of Saint John Lateran, 276-93
Carola Jäggi, MATER ET CAPUT OMNIUM ECCLESIARUM: Visual Strategies in the Rivalry between San Giovanni in Laterano and San Pietro in Vaticano, 294-317
Peter Cornelius Claussen, The Remodelling of San Giovanni in Laterano by Pope Nicholas IV: Transept, Apse and Façade, 318-44
Daniela Mondini, Furtum Sacrilegum: The ‘Holy Heads’ of Peter and Paul and their Reliquaries in the Lateran, 345-78
Andrea De Marchi, Reconsidering the Traces of Gentile da Fabriano and Pisanello in the Lateran Basilica, 379-99
John F. Romano, The Rite of Reconciliation of Penitents at the Lateran Basilica, 400-27
Nadia Horsch, The New Passion Relics at the Lateran, Fifteenth to Sixteenth Centuries: A Translocated Sacred Topography, 428-65
Alessandro Ippoliti, The East Façade of the Complex of Saint John Lateran in the Modern Era, 466-91
Filip Malesevic, The Book of Acts in the Constantinian Basilica: Cardinal Cesare Baronio and the Navata Clementina in San Giovanni in Laterano, 492-522


[1] R. Krautheimer, S. Corbett, A. K. Frazer, Corpus Basilicarum Christianarum Romae, V, Vatican City 1977, 27, following A. M. Colini. The phrase egregiae Lateranorum aedes is from Juvenal, Sat. 10.15-18.

[2] Krautheimer et al. (as in n. 1), 82 Fig. 80; S. De Blaauw, Cultus et decor. Liturgia e architettura nella Roma tardoantica e medievale, Vatican City 1994, II, Fig. 2; H. Brandenburg, Die frühchristlichen Kirchen in Rom, Milan/Regensburg 2004, 261, II.9.

[3] L. Duchesne, ed., Le Liber pontificalis, I, Paris 1886, 172; tr. R. Davis, The Book of Pontiffs (Liber Pontificalis), Liverpool 1989, 16.

[4] Transcribed by P. Lauer, Le Palais de Latran, Paris 1911, 585.