To an approximate scale of 1:660

[a]erariu[m]. romanu[m]. (‘Roman treasury’); [measurements]

• c.1513/14
  Datable to c.1513/14

Pen and brown ink and grey-brown wash over stylus lines and compass pricks

Bernardo della Volpaia

The rotunda generally known as the Temple of Romulus, after the deified son of the emperor Maxentius, is situated just east of the Roman Forum, facing the Via Sacra between the Temple of Antoninus and Faustina and the Basilica of Maxentius. This modern name, based largely on a spurious medieval legend, has not been substantiated, and the structure appears to have been built well after Maxentius’s time, during the second quarter of the fourth century (Tucci 2017, 2, pp. 491–556). Its function was to provide access from the Via Sacra to the pre-existing halls behind, which are reached from a portal at the rotunda’s rear but are on a different axis (LTUR 1993–2000, 1, pp. 324–25). These halls project forward from the Forum of Peace beyond to the northeast, and they apparently formed part of this second/third-century complex, before their conversion into the church of Santi Cosma e Damiano by Pope Felix IV (r.526–30). The belief that they originally served as the city’s treasury (aerarium), which is recorded by the drawing’s caption, is of uncertain origin although it was shared by an anonymous writer from the early fifteenth century (Valentini–Zucchetti 1940–53, 4, pp. 144–45; Tucci 2017, 2, p. 763). A similar view would later be expressed by Antonio da Sangallo the Younger, who made a drawing of the side wall of the halls, which he annotated with the caption La Zecha anticha a san chosimo e damiano (‘the ancient mint at Santi Cosma e Damiano’; see Kantor-Kazovsky 2011, pp. 259–62).

The Coner drawing records the complex before its major restructuring in the early seventeenth century, when the church was almost completely rebuilt (save for the sixth-century apse) and a new floor was inserted (from 1630) to raise the interiors well above the level of the ancient paving (Tucci 2017, 2, pp. 859–925). Although it has no obvious connections with other surviving depictions from the period, it still has the hallmarks of being closely based on an original and carefully executed survey. First, it correctly represents the angle at which the rear halls join the frontal rotunda, which distinguishes it from a sketch layout previously executed by Francesco di Giorgio or, later, from Lorenzo Donati’s plan, or those now in Oxford and Paris produced by Pirro Ligorio, all of which show them on the same alignment; secondly, it evidently records only those parts of the complex that were extant and accessible, therefore omitting the interior of the small frontal hall to the left of the rotunda (which probably no longer survived), and the external lines of walls that – presumably – could not be properly inspected; and, thirdly, it is annotated with a comprehensive set of measurements. The accuracy of the Coner plan can be judged by comparing it to modern-day archaeological plans and reconstructions (e.g. Tucci 2017, 2, pp. 494 and 717). The internal diameter of the rotunda, for example, is given as 25 braccia (14.5m), which is very close to the actual dimension. The main difference is that the space behind the church’s apse is shown as being much deeper than in reality, although the proportions of the church’s square interior are notably more reliable than, say, Ligorio’s part-reconstructed plan in Paris, which shows it as being much longer. Numerous much smaller features seem likewise to be based on a reliable source or perhaps even first-hand knowledge, such as the trios of recesses in the three walls behind the church apse, although the positions of the openings and recesses inside the rotunda have been regularised, and the frontal staircases to either side of it are seemingly invented. These early investigations of the complex must have been conducted during Bramante’s lifetime, and so may well be contemporaneous with Bramante’s late Palazzo Caprini façade which had a rusticated basement with shopfronts based in design on the rusticated portal that still survives on the church’s right flank (Hemsoll 2019b, pp. 157–58; Hemsoll forthcoming). A record of an internal moulding of the church appears in another drawing.

OTHER IMAGES MENTIONED: [Francesco di Giorgio] Florence, GDSU, Taccuino del Viaggio, 330 Av (Bartoli 1914–22, 6, p. 7; Burns 1993, p. 343–46); [Antonio da Sangallo the Younger] Florence, GDSU, 992 Ar (Bartoli, 1914–22, 6, p. 91; Kantor-Kazovsky 2011, pp. 259–62; Frommel–Schelbert 2022, pp. 80–81); [Lorenzo Donati] Florence, GDSU, 209 Av (Bartoli, 1914–22, 6, p. 107); [Pirro Ligorio] Oxford, Bodleian Library, Canon. ital. 138, fols 13v, 15r, 160v (Tucci 2017, 2, pp. 771 and 783–90; Campbell 2016, p. 19-20, 22, 250); [Pirro Ligorio] Paris, BNF, Ms. Italien 1129, fol. 343 (Tucci 2017, 2, pp. 771 and 783–90)

OTHER DRAWINGS IN CODEX CONER OF SAME SUBJECT: Fol. 67r/Ashby 113

Ashby 1904, pp. 22–23
Census, ID 44191

Drawing

Digitisation of the Codex Coner has been made possible through the generosity of the Census of Antique Works of Art and Architecture Known in the Renaissance, Berlin.

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