The Milan Church of Sant’Ambrogio

Introduction

A new history of so famous a church as Sant’Ambrogio at Milan requires some justification. Mine is set forth in this book’s opening chapter, which deals with the original records of a nineteenth-century archaeological excavation inside the church. Many are examined here for the first time, revealing factual information that cannot be reconciled with the conventional reconstruction of the building history. Most importantly, they point to a different identification of the remnants of the first church on the site, from the Romano-Christian period, hence shed new light on the origins of the present church that replaced it in the Romanesque period. Ultimately, this leads to a substantial revision of the building history from the fourth century to the twelfth, and even helps resolve a great controversy among scholars over the approximate dates of construction of the present Romanesque church. Several other open questions likewise find their answers.

The first chapter establishes the theoretical framework of the entire book. It examines the records of the excavation, shows how they disagree with a theory that underlies the conventional view of the building’s origins, extracts from the records the site’s stratigraphy, and on these grounds formulates a new theory in broad outline. The subsequent chapters present a detailed history of the old church and the present one according to the new theory, and with due attention to primary documents attesting to their changing nature. This detailed history may be seen in two ways: for the initiated, as a wide-ranging test of the theory; for the uninitiated, also as an introduction to the manifold aspects of this fascinating building. All things considered, a fundamental advantage of the proposed theory may be noted. Unlike the conventional one, it leaves no part of the building unexplained, and requires no unfounded assumptions on supposedly lost but unattested structures. The principle of Occam’s razor thus favours it. Speculation on secondary issues occasionally proves tempting, but none is essential to the theory.

From the second chapter to the last, the book covers all phases of the building over some eight hundred years from the fourth to the twelfth century. Each phase is considered from several complementary viewpoints: the historical circumstances of construction; the expectations of patrons; the ←ix | x→urban preconditions of the time; the structural issues faced by the builders; and architectural design, usage, fixtures, decorations, and the significance of all for contemporary and subsequent generations. Yet one important subject is largely left out. With few exceptions, this study avoids the assessment of sources of influence and architectural developments, as reflected in comparable buildings at Milan and elsewhere in northern Italy. The reason for this omission is the uncertain and indeed disputed chronology of the various buildings. This book addresses the issue of dates with regard to Sant’Ambrogio alone, on the basis of internal evidence, in the hope that the conclusions reached will facilitate future studies on the wider regional scale.

Chapter 1

Theoretical Models of the Building History

1.1 The Records of a Nineteenth-Century Excavation

In the year 386, St Ambrose consecrated a church just outside the Roman city of Milan. Named even in his lifetime ‘Basilica Ambrosiana’, it was intended for his own burial beside the relics of martyr saints. In time it gave way to the present church of Sant’Ambrogio, which still treasures his relics and theirs. This celebrated building is something of an archaeological puzzle, combining diverse medieval structures of uncertain history. To introduce them in terms of the current scholarly disagreements on the exact periods of construction, these are (Figs. 1 and 2): a two-storey choir of disputed date between the ninth century and the mid-eleventh; a distinct High Romanesque nave of the later eleventh century or perhaps the twelfth; a corresponding entrance atrium of similarly unsettled date; and an integrated tower that contrasts with another, detached from the building and unclearly related to it. Inside the church, the chancel is raised on a platform at the eastern end of the nave, accommodating above the altar an early medieval ciborium of particularly controversial history. All controversies, moreover, seem to be at an impasse.¹

Some information on the nineteenth-century discoveries is given in publications of the time, including a chronicle of events and amply illustrated studies of the church. The chronicle consists of the letters written by the local priest, Francesco Maria Rossi, during the main restoration period from 1857 to 1876.² In an intermediate publication of 1864, the priest and teacher Luigi Biraghi discusses the first finds of the excavation from the standpoint of ecclesiastical history. Two later studies deal with the subject in tandem with a thorough examination of the church as a building. The first, sometime before 1882, is a weighty treatise by the French engineer and scholar Fernand de Dartein.³ In addition to painstaking descriptions, it offers a certain theoretical model of the sequence of structures on this site from the fourth century onwards. The restoration architect Gaetano Landriani follows in 1889 with a book rich in his own observations, but otherwise based on the same theoretical model. The two studies are, in effect, correlated, as both authors attest to having ←2 | 3→exchanged information.⁴ All four works subscribe to a fundamental fallacy, then common but now inconceivable, in that all assign the Romanesque nave and atrium to the much earlier Carolingian period. As primary records of the restoration and excavation, they are nevertheless invaluable.

The excavation emerges from these sources as a pious search for holy relics mixed with genuine archaeological exploration of the building’s origins. It advanced in several distinct stages. The first was prompted by the state of the ciborium, as its columns appeared half buried in the chancel platform, therefore earlier in date. Partly unearthed in 1863–64, the columns were found to descend more than a metre below the platform surface. Between them, directly under the altar, the restorers uncovered a sealed porphyry sarcophagus perched on a pair of empty tombs.⁵ There the excavation halted for almost three years, and then proceeded cautiously. In late 1866 it resumed around the ciborium, and in 1867 advanced to the surrounding area under the chancel platform. This time the finds included lesser tombs alongside the remnants of old floors from several different building periods.⁶ Other finds accumulated up to 1869, revealing the early history of the nave. Though now divided into aisles by arcades on heavy piers, it was once a much lighter structure divided by colonnades. Two rows of disused column foundations came to light, and even with a couple of column bases still in place.⁷ Finally, in 1871 the porphyry sarcophagus was opened to reveal the bones of the saints.⁸

Unfortunately, most of the finds soon disappeared. In the nave, a new floor covered all but a few vestiges of the old colonnade foundations. In the chancel, a misguided alteration eliminated the original arrangement. The ciborium was hoisted up whole onto the present chancel platform;⁹ the excavated space under the platform was then rebuilt as a burial chamber of the restorers’ own invention; and a new shrine for the saints was installed inside it.¹⁰ The bulk of the information therefore comes from prior documentation, of which the most accurate and specific is graphic rather than textual.

Besides the illustrations in the printed books, the graphic documentation comprises a large quantity of manually drafted originals. Some are kept in the archive of Sant’Ambrogio; others belong to the Beltrami Collection (Raccolta Beltrami) in the civic archives at Milan castle, the Castello Sforzesco. All illustrate the existing building, but a fair number add the finds of the excavation. These include otherwise unknown plans and sections, ranging in quality from rough sketches to professional measured drawings, and often inscribed with measurements and notes. A detailed analysis of each is given below in catalogue form.¹¹ One purpose of the catalogue is to establish the chronology of these primary documents, as dates are rarely given but may be deduced from the dated writings about the course of the excavation. The most informative are Rossi’s letters, supplemented by recently published materials from the private archive of Fernand de Dartein.¹² Once arranged chronologically, the documents can ←3 | 4→be seen to combine facts and hypotheses. As the facts accumulate from the earlier documents to the later, the hypotheses change.

The earliest graphics reflect the narrow scope of the 1864 excavation, confined as it was to the eastern side of the altar and ciborium.¹³ A general view of the finds is given in Biraghi’s book of that year (Fig. 3). Two columns of the ciborium appear fully exposed, down to the cubic plinths on which they still stand. The porphyry sarcophagus half hides in the shadows under the altar, partly encased in brick and positioned across the lower tombs. The broader setting is blurred, and proportions seem distorted,¹⁴ but a semi-faded drawing in the Sant’Ambrogio archive compensates for these deficiencies. This is a longitudinal section of the building from mid-nave to the choir entrance, lower parts only, and comprising in the chancel the same excavated elements with precise measurements (Fig. 4, a–b). Apparently made sometime between 1864 and 1866, this document too is limited in scope. It illustrates the situation in the area east of the tombs, but reveals no awareness of the 1867 finds to their west.¹⁵ Based on initial and incomplete information, all documents of 1864–66 contain a certain ←4 | 5→←5 | 6→←6 | 7→measure of unreliable guesswork. Under the ciborium plinths, for instance, they depict a hypothetical floor which fails to match any of those eventually found in reality (cf. Fig. 5).¹⁶ The later documents duly omit it.

Covering a wider area of the chancel, the 1867 information complements and amends the above. Rossi relates the discovery of previously unknown floor remnants and many more tombs, mostly plain sarcophagi.¹⁷ The details, in his account sparse, emerge piecemeal from a substantial body of graphic documents. Some have already been studied and published,¹⁸ and others are presented here for the first time. Once organized, the seemingly separate documents reveal a coherent whole.

In particular, a systematic dossier may be reconstructed from two sources: its secondary copies in the Beltrami Collection, and primary material in the archive of Sant’Ambrogio. The copies, done on tracing paper, comprise four interrelated architectural drawings of professional quality (Fig. 6, a–d). There is a detailed plan of the chancel area with all the floor remnants and some tombs, a matching longitudinal section inscribed with measurements, and a cross section in two staggered parts. The section lines are indicated on the plan, and a consistent set of reference symbols is used throughout.¹⁹ Separately at Sant’Ambrogio, two pages from the original dossier still exist, and still tied together with a string (Fig. 7, a–b). One carries a colour version of exactly the same plan on the same scale (1:50), the other various annotations including a full legend for the same reference symbols. The section drawings are missing but must have once existed, since the legend covers them precisely as known from the copies.²⁰ Hence, the complete dossier is available in one form or another. It amounts to a considered presentation of the excavation results up to 1867, the earliest of its kind, and the evident source for later presentations in print. An engraving published by Dartein (Fig. 8), for instance, is based primarily on the plan and longitudinal section of the same dossier, although it omits some details and imports others from the earlier graphics of 1864–66.²¹

The author of this important dossier may be identified with certainty as the aforementioned Gaetano Landriani, who started work on this site as a humble draughtsman and eventually reached the position of executive architect of the restoration.²² His signature appears on both the plan and the annotations at Sant’Ambrogio. In his book he describes himself as the surveyor behind Dartein’s engraving, and Dartein duly acknowledges his efforts in the margin of this engraving.²³ The plan he received from Landriani even survives in his private archive.²⁴ Landriani should moreover be credited with a group of annotated pencil sketches, all in the Beltrami Collection (e.g. Figs. 9–14), because these contain the unedited raw material for the final plan and sections of the dossier.²⁵ Apparently made on-site in the course of the 1867 excavation, the sketches cover much more besides. Some explore fine detail otherwise ignored; others attest to initial reflections, as yet unaffected by the theory that twenty-two years later, in 1889, would dominate his book. As will be seen here, the primary documentation and the book are worlds apart. The first is the work of an unassuming but admirably observant surveyor, while the second succumbs to a problematic theory unsupported by his own findings.

A serious gap in the excavation record concerns the colonnaded phase of the nave. Except for a few portions of foundation reported in 1864,²⁶ all the relevant discoveries are those made in a separate and poorly documented excavation of 1869.²⁷ The subsequent publications speak of more column foundations, along with two column bases and some floor vestiges, but no trace of any outer walls other than the present.²⁸ The first graphic record of the column foundations is found in a grand plan of the existing building, undoubtedly Landriani’s, and post-dating 1870. Now reduced to a lone fragment but known by an old photograph (Fig. 15), this is a summary plan of the restoration with no more than a generalized indication of the excavated material. The plan printed in Landriani’s book is based on this one and gives no further details.²⁹ In section, nothing covers the colonnaded nave beyond a generic single column. Its floor level is given only in relation to the present nave, whose own floor is no longer the same as it was at the time of the excavation.³⁰ No primary document correlates this floor with any of those recorded earlier in the chancel. Subsequent reconstruction essays do, but always selectively to suit a particular interpretation. In effect, the place of the colonnaded nave among the various finds remains undocumented.

Otherwise, the documents provide cumulative information on the relative position of past and present structures, notably metric measurements of depth for floors, bases, and tombs. To gain a full picture, this study collates in tables those given in groups of documents, quoting them in centimetres and in descending order. However, a glance at most tables reveals a major difficulty: the measurement systems vary (e.g. Tab. I). There are essentially three. The earliest, typical of 1864–66 and later sporadic, involves separate measurements from one point to another with no fixed zero reference (in the table, e.g. column D.1.). Consecutive ones may be combined, in which case the result is given in the table in brackets. Another system appears concurrently but gains traction only in Landriani’s sketches of 1867. It involves running measurements of depth, all taken from a strictly horizontal line that serves as a zero reference (e.g. D.6. & D.11.). Presumably using ropes and planks, Landriani seems to have set in the actual building several different reference lines of this kind, some corresponding to tangible objects, others arbitrary. As a result, few sketches share the same zero setting. Finally, one of these settings recurs in the 1867 dossier, governing about half its measurements (D.15.). Here distinguished from the rest and titled ‘System 3’, this set of measurements overlaps the others. Therefore, all systems can be converted into this one. The converted values, emphasized, appear in the tables in parallel to the originals as given in the documents.

The conversion enables comparison and correlation on the basis of System 3. A master table (Tab. I) compares in this way the measurements for floors and bases as given in five longitudinal sections, each from a different stage of the excavation.³¹ The result inspires confidence in the accuracy of the documents, as most parallel measurements can be seen to differ by no more than a negligible 1 cm. Greater differences exist, in this table and others, but any exceeding 3 cm are very rare and demonstrably mistaken.³² The same comparison also reveals something of the relative importance of the various documents. For example, Dartein’s longitudinal section (D.16., Fig. 8) emerges in this table as a secondary source, converting measurements from two others in exactly the same way as here (cf. D.15. & D.1.). Though useful as a graphic illustration, it can otherwise serve only for a countercheck. All things considered, the table establishes a standardized and reliable series of measurements in accordance with System 3 (last column, ‘std.’). Several finds of the excavation are missing, notably the colonnaded nave and the tombs, but all may now be correlated with the same system provided their depth is given by any source in relation to anything in this standard series. The final aim of the procedure is to establish a complete sequence of floors, and with it the number and sequence of building periods up to and including the Romanesque.

Reference symbols are a problem because the documents employ several different systems, the research literature adds more, and none covers everything.³³ Instead, the following discussion refers to each floor and base level by its measurement in System 3, as given in the master table. For example, the floor of the Romanesque chancel platform is the one ‘at −102’, in this form indicated also in the margin of relevant illustrations (e.g. Fig. 4, b). In Tables I–V and throughout the catalogue, different displays serve to facilitate navigation: on plain ground, all parts of the present building as it was at the time of the restoration; on shaded ground, anything discovered underneath it. This division is also the first step towards a more detailed identification of the building periods.

1.2 The Present Church Building according to Its Floor Levels