Workshop of Andrea del Verrocchio, circa 1470, traditionally attributed to Leonardo da Vinci
- Workshop of Andrea del Verrocchio, circa 1470, traditionally attributed to Leonardo da Vinci
- Drapery Study of a Kneeling Figure Facing Left
- Drawn with the brush in brown-grey wash, heightened with white, on linen prepared grey-green, laid down on paper;
Numbered in brown ink: X
thence by inheritance to his widow Anna Maria de Groote, then probably to their elder son, Everhard Jabach (1658-1721);
acquired by Pierre Crozat, Paris, at an unknown date between 1695 and 1721, his sale, Paris, 10 April 1741, part of lot 5, catalogued by Pierre Jean Mariette, as Leonardo,
acquired by Jean-Baptiste-François Nourri;
an unidentified black chalk paraphe on the verso of the backing sheet;
thence by inheritance to his son-in-law, Henri Dumesnil (L.739),
his sale, Paris, 10-12 May 1900, lot 255, as Leonardo;
Comtesse Martine Marie-Pol de Béhague;
Marquis Hubert de Ganay;
Marquis Jean Louis de Ganay,
his sale, Monaco, Sotheby's, 1 December 1989, lot 73, as Leonardo
Vinci, et al., La Raccolta Leonardesca della Contessa de Béhague, 1980-81;
Paris, Louvre, Leonard de Vinci: Dessins et manuscrits, 1989-1990, (catalogue by Françoise Viatte), no. 8
B. Berenson, The Drawings of the Florentine Painters, Chicago 1938, vol. I, p. 62, vol. II, no. 1071A, vol. III, fig. 525 (as Leonardo);
K. Clark, Leonardo da Vinci, Cambridge 1939, p. 12, under note 1 (as Leonardo);
B. Berenson, I Disegni dei Pittori Fiorentini, Milan 1961, vol. I, p. 102, vol. II, p. 211, no. 1071A, vol. III, fig. 445 (as Leonardo);
C. Ragghianti and G. D. Regoli, Disegni dal modello, Pisa 1975, p. 31, under note 10 (as Leonardo);
G. D. Regoli, ‘Il piegar de’panni’, Critica d’Arte, XXII, November-December 1976, pp. 47-48, under note 16 (mentions de Ganay group and attributes them to Leonardo);
A. Vezzosi and C. Pedretti, La Raccolta Leonardesca della Contessa de Béhague, Vinci 1980, p. 19, fig. 2 (as Leonardo);
A. Vezzosi and C. Pedretti, Leonardo’s Return to Vinci, The Countess of Béhague Collection, New York 1981, p. 21, fig. 2 (as Leonardo);
J. Snow-Smith, The Salvator Mundi of Leonardo da Vinci, Seattle 1982, pp. 53-54, fig. 51 (as Leonardo);
J. Cadogan, ‘Linen Drapery Studies by Verrocchio, Leonardo and Ghirlandaio’, Zeitschrift für Kunstgeschichte, 1983, vol. 46, p. 56, fig. 22, reproduced (as Leonardo);
Leonardo da Vinci, exhib. cat., London, South Bank Centre, 1989, p. 50, under cat. no. 3 (as Leonardo);
D. Scrase, ‘Paris and Lille, Leonardo: Italian Drawings’, The Burlington Magazine, February 1990, pp. 151-153 (as Leonardo);
K. Christiansen, ‘Leonardo drapery studies’, Burlington Magazine, August 1990, p. 572 (as Ghirlandaio);
D.A. Brown, Leonardo da Vinci: Origins of a Genius, London 1998 (discusses the group exhibited in 1989 and attributes it to Verrocchio and his Workshop);
P.C. Marani, Leonardo una carriera di pittore, Milan 1999 (as Verrocchio and his Workshop);
B. Py, Everhard Jabach, collectionneur (1618 – 1695), Paris 2001, pp. 20 and 274;
Leonardo da Vinci, Master Draftsman, exhib. cat., New York, The Metropolitan Museum of Art, 2003, pp. 116 and 119, under note 18;
Leonard de Vinci. Dessins et manuscrits, exhib. cat., Paris, Louvre, 2003, p. 56, under note 6, p. 57 and note 18 (as Leonardo);
C. Bambach, ‘Leonardo and drapery studies on ‘tela sottilissima de lino’’, Apollo Magazine, January 2004, p. 53, under note 30 (as Verrocchio);
B. Py, 'Everhard Jabach: Supplement of Identifiable Drawings from the 1695 Estate Inventory,' Master Drawings, vol. XLV, no. 1, 2007, p. 6, and p. 36 note 15;
A. Gauthier, ‘From Crozat to The Musée des Beaux-Arts, Rennes: The Origins of the Drawings Collection of the Marquis De Robien’, Master Drawings, vol. XLV, no. 1, 2007, p. 95;
L. Bicart-Sée, 'Some Archival References for Jean-Baptiste-François Nourri,' Master Drawings, vol. XLV, no. 1, 2007, p. 88;
G. Aubert, ‘From Crozat to the Musée des Beaux-Arts, Rennes: The Origins of the Drawings Collection of the Marquis De Robien,’ Master Drawings, vol. XLV, no. 1, 2007, p. 95
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."
These two remarkable drapery studies from the Barbara Piasecka Johnson Collection belong to a hugely important group of some 16 similarly drawn draperies on fine linen (‘tela sottilissima di lino’), which bear witness to the brilliance and originality of one of the most important of all Renaissance workshops, that of Andrea del Verrocchio (circa 1435-1488). There sculpture, painting and architecture came together in a unified artistic expression of monumentality, anticipating what Vasari would later describe as the nuova maniera. The achievements of Verrocchio’s workshop were essentially the product of his own incredible vision and talent, but also grew out of the innovative contributions of the various brilliant young artists in his bottega, most notably the young Leonardo da Vinci, who seems to have begun his apprenticeship between 1464 and 1469. Leonardo joined Verrocchio’s workshop more or less at the peak of the master’s career, when he was involved in major commissions for the Medici family, having rapidly taken over the mantle of the family’s favourite artist after the death of Donatello in 1466. Interestingly in the context of these drapery studies, Donatello was the first sculptor to experiment, already in the middle of the 15th century, with the use of actual fabric in casting the draperies of his figures, a famous example being the bronze of Judith and Holofernes, in Palazzo Vecchio, Florence.
This was a time of great dynamism and change, to which an innovative and restless intellect such as Verrocchio was perfectly suited. Vasari characterized Verrocchio not only as an artist interested in painting and sculpture, but also as a studioso who devoted time to ‘scienze’ and ‘geometria’, and a ‘musico perfettissimo’.1 His workshop was famous even beyond the borders of Tuscany as an educational centre for young artists, and in the mid-1470s no other workshop in Florence was producing comparable quantities of important paintings. Verrocchio’s bottega embodied the highest formula of success for a Renaissance workshop, namely total command of different media.
The pivotal group of 16 drapery studies to which the Johnson drawings belong were produced in the febrile environment of Verrocchio’s studio during the 1470s, and constitute a unique contribution to the history of Italian Renaissance drawing. From this group, only the present two drawings remain in private hands; the others are all in European public collections.2 It was Giorgio Vasari, in the second (1568) edition of his Lives of the Artists, who first credited Leonardo da Vinci with having invented the highly experimental and original technique seen in these studies: drawn with the point of the brush in tempera, heightened with white body-colour, on finely woven linen prepared with a thin layer of grey-green, these remarkable drawings are at once both painterly and sculptural. If Vasari was correct in attributing the invention of this technique to Leonardo, the teenage prodigy clearly transformed both the technique and usage of drapery studies.
Vasari’s description of Leonardo’s drapery studies on tela di lino follows his mention of the young artist’s apprenticeship in the bottega of Verrocchio. Vasari writes that Leonardo ‘studiò assai in ritrar di natural’ and continues: ‘e qualche volta in far modegli di figure di terra; e adosso a quelle metteva cenci molli interrati, e poi con pazienza si metteva a ritrargli sopra a certe tele sottilissime di rensa o di panni lini adoperati, e gli lavorava di nero e bianco con la punta del pennello, che era cosa miracolosa, come ancora ne fa fede alcuni che ho di sua mano in sul nostro Libro de’ disegni’ (and sometimes in making models of figures in clay, over which he would lay soft pieces of cloth dipped in clay, and then set himself patiently to draw them on a certain kind of very fine Rheims cloth, or prepared linen: and he executed them in black and white with the point of the brush, so that it was a marvel, as some of them by his hand, which I have in our book of drawings, still bear witness).3 Although Vasari mentions that he himself owned some of these studies, none of the surviving examples are on his distinctive mounts, nor can any be associated with him by other means; yet clearly Vasari was not only familiar with these works, but also fascinated by the visual effect and remarkable impact of these revolutionary studies on linen.
Yet despite this subsequent acclaim, drapery studies of this kind, drawn with a technique that transcends the boundaries between drawing and painting – and indeed sculpture – seem not to have been popular with the following generations of Florentine artists, and were only produced during a brief period during the last quarter of the 15th century, although some of them, such as the famous Drapery study for a seated figure in the Louvre4 (a drawing that is accepted by the majority of scholars as the work of Leonardo himself), were copied at the time, and reused in paintings well into the sixteenth century.5
The two Johnson studies, executed in the bottega of Verrocchio in the 1470s, were clearly drawn from three-dimensional models consisting of an underlying figure made of wood, clay or wax, draped with real cloth dipped in liquid clay or wax that has been arranged so as to create deep folds and draperies, emphasising the sculptural qualities of the ensemble, an effect that is enhanced in the drawings through the carefully and brilliantly applied white distemper.
In the first study of a kneeling figure, unlike the other drawings in the group, there is no obvious indication of a mannequin underneath, yet the complex forms of the folds do provide a clear sense of a body beneath, and also create an impression of the folded left arm, which acts as a divider for the upper part of the body. The deep and intricate folds are studied in a subtle and coherent way, without losing the overall effect of elegance and harmony. The sculptural symmetry and dynamism of the mantle is enhanced by the skilful chiaroscuro effects: a flash of light falls theatrically from the left. The artist has here used very subtle shades and gradations of grey-green, but it is the white distemper that captures the light, helping to distinguish the variety of folds. These highlights somehow manipulate the pose and create vitality, in striking contrast to the fundamentally static elements of this monumental, powerfully rooted image, enhancing the three-dimensional effect of the cascading mantle. As Françoise Viatte noted in her 1989 Louvre exhibition catalogue entry for this drawing, there is a close similarity between the forms of these draperies and those of another drapery study of a kneeling female figure (fig. 1), formerly in the Malcolm collection and now in the British Museum (where currently listed as Leonardo da Vinci), writing: ‘L’attitude correspond à celle de l’étude de la collection Malcolm,….Le profile est plus marqué ici et le corps n’est pas indiqué…..’. 6
In the second Johnson study, which shows a standing figure, in profile and looking to the right (see following lot), the outlines of a lay model can, in contrast, be easily discerned, its right arm folded and resting on its chest, while at the top of the drawing we see the lightly suggested outlines of the neck. These quick notations of a mannequin, drawn with the point of the brush in a dark shade of grey, help the viewer to understand the fall of the draped cloth and the position of the body beneath. The light, which falls dramatically from the right, is, however, concentrated only on the draped cloth, leaving in darkness the back of the figure and the upper part of the body, as well as the last ample fold of cloth just below the arm. Like the kneeling study, this drawing is very subtly executed with the point of the brush and different shades of grey-green tempera, heightened with white distemper which captures the light. The focus on a side view of the cascading, draped cloth is paralleled in another drawing from the group, in the Louvre, where the model appears slightly more rotated to the left, and the drapery is studied from a closer viewpoint.7
Carmen Bambach has suggested that the technique of painting drapery studies on linen support had its origin in ‘practicality…as fine woven fabric provides a more durable and flexible support than paper for the application of a layer of tempera pigment.’8 This must indeed have been an important factor in the choice of support, combined with the fact that the surface of the linen catches the light very differently from paper, creating a visual texture that is a singularly effective and appropriate vehicle for a drapery study. Both the Johnson drawings seem to encapsulate Leonardo’s theoretical views on the depiction of drapery, as articulated in one of his notes for an ultimately unrealised treatise on art, where he emphasised that drapery is most correctly rendered when life is sensed beneath and not when it is simply a mass of cloth falling from a body, as many artists seem to think it should be depicted, without properly considering the overall effect.9
In 15th-century Italy there was a well-established tradition of artists seeking inspiration from antique art, and especially from antique sculpture, which they studied and copied relentlessly. Although this reverence for antiquity would, of course, endure for centuries to come, the developing practice of drawing from life gave rise to a completely different approach to the study of the human body. This practice of life drawing, ritrar di natural, was fundamental in enabling young artists (or even experienced masters) to develop their ability to create and communicate the infinite variety of poses required to paint or sculpt successfully. Above all, life drawing helped them understand and master the use of light in depicting a figure; yet in drawings such as these, the light almost becomes the subject, and in their near-abstract impact, these astonishing works transcend their period of creation, and are both essentially modern and fundamentally timeless.
Given their technique, with carefully applied layers of tempera and only very slight, outlined underdrawings, these studies on linen are executed in what Popham already described in 1946 as an ‘impersonal medium’, where the personal ductus of an individual artist is rather hard to identify.10 It is therefore not surprising that opinions continue to differ regarding the attribution of individual studies within the group. In a workshop such as Verrocchio’s, several artists would probably have drawn the same three-dimensional model at the same time, from different viewpoints, and the style and execution of the works they produced, under the close direction of the master, would have been rather similar. Verrocchio would have seen drawing instruction as a key way to shape the style of his young apprentices, thereby guaranteeing the greatest possible uniformity of execution when he and his studio assistants worked together on the paintings that would issue forth from his studio, under his name. Yet even if there is no clear consensus of opinion regarding the attribution of these drapery studies, as Carmen Bambach observed at the outset of her 2004 article, little can match ‘..the aesthetic beauty, monumentality of expression, and technical innovation of the much-debated group of drapery studies painted in tempera with the brush on finely woven linen, prepared with a thin layer of blue-green, grey, or beige, or nearly brown colour.’ 11
What is, perhaps, surprising is the fact that so few drapery studies like these two have survived, given the importance of Verrocchio’s workshop and the studio assistants it produced,12 the general tendency at the time for drawings to be kept together as a sort of graphic archive of the studio, and the fact that the technique in which these particular works were made was seen even by Vasari, hardly a century later, as extraordinarily original and brilliant.
The History of the Drawings, and of their Attribution:
The journey taken by the 16 surviving drapery studies of this type from their creation in the 1470s to the present day is clearly a fascinating one. Regarding the first 150 years or so of the story, we know nothing, but during these years – and maybe even at the time of their creation – eight of the studies, including both the Johnson drawings, were inscribed, some by the same hand, in the upper left or right corners with numberings in Roman numerals, drawn with the point of the brush in brown ink. The highest of these numberings is, however, XIII, so at least five more drawings must originally have borne these numbers than do so today. There is no way of knowing whether those five were surviving drawings from which the numbers have subsequently been cut, or additional sheets that are now lost.
In the collection of Everhard Jabach (1618-1695), as by Albrecht Dürer
In 2001, Bernadette Py published the highly important discovery that fourteen of the sixteen surviving drapery studies, including the two from the Johnson Collection, had been in the collection of the German-born banker and great collector, Everhard Jabach (1618-1695), thereby adding a vital passage to the provenance of this group of drapery studies.13 The drawings appear in the posthumous inventory of Jabach’s collection, compiled on 6 March 1695, but this reference had previously gone unnoticed because in this inventory the drawings are attributed to Dürer: ‘Études de draperie d’Alber Dure [Durer] sur toile collée sur papier et haussé de blanc en détrempe’. It would be fascinating to know where and when Jabach acquired the drapery studies, and also when and how the association with Verrocchio’s workshop was lost. Py’s conclusion was that the attribution to Dürer was simply the result of the fact that at that time no signed drapery studies by Leonardo were known, whereas others bearing Dürer’s distinctive monogram were very familiar.14 In any case, the fact that the connection of this important and rare group of drawings with Verrocchio and Leonardo had, relatively rapidly, been totally lost, suggests that they had left Italy at a fairly early stage, probably some considerable time before they were acquired by Jabach. It is also interesting to note, in this context, that Jabach had acquired more than a thousand drawings from Lady Arundel in 1653,15 and it is tempting to speculate that this might have been the route by which the drapery studies entered Jabach’s collection; they are certainly the type of works that might have appealed to the Earl of Arundel’s extraordinarily discerning eye.
While in the Jabach collection, it seems that the white heightening in many of the drapery studies was embellished, an issue discussed, in relation to the drapery studies in the Louvre, by both Viatte and Bambach,16 and which has also been extensively studied by Catherine Monbeig Goguel. In the Johnson Drapery Study of a Kneeling Figure Facing Left, an area of thicker, denser white pigment is apparent in the lower part of the draped mantle, which contrasts with the much more lightly applied white distemper on the rest of the study, and in the Drapery Study of a Standing Figure Facing Right there is a small area of densely applied white to the lower right of the draped cloth, which appears to disguise an area of abrasion.
In the collection of Pierre Crozat (1665-1740), as Leonardo da Vinci
The first documented occasion when the drapery studies were attributed to Leonardo da Vinci was when they appeared in the month-long sale of the great collection of Pierre Crozat (10 April-13 May 1741), a catalogue written by none other than that supreme drawings connoisseur, Pierre Jean Mariette. Lot 5, attributed to Leonardo da Vinci, was described as: ‘Dix-huit, idem, dont plusieurs études de Têtes et de Draperies’. In his own copy of the Crozat sale catalogue, however, Mariette wrote: ‘4 P. [ pieces?] testes, le reste pour de robes’, so fourteen of the eighteen items in the lot were drapery studies – clearly the fourteen sheets formerly owned by Jabach.17 Crozat owned a large number of drawings from the Jabach collection, but it is not known when he acquired them; perhaps, as Py has suggested, they were bought between 1695 and 1721, probably from Jabach’s elder son, also named Everhard Jabach (1658-1721).18
In the collection of Jean-Baptiste-François Nourri (1697-1784), once more as Dürer
The Conseiller Nourri, who purchased the lot including the drapery studies at the Crozat sale, must have bought some of the drawings for other collectors or sold them afterwards, as by the time of his own sale, in Paris on 24 February 1785, only two drapery studies, not including either of the Johnson drawings, remained: they were included, under the name of Albrecht Dürer, within lot 736: ‘Sept compositions et etudes; à la plume et au bistre rehaussées dè blanc, dont une étude de femme et deux de draperies’.
In the collection of Pierre Defer (1798- 1870), and by descent to his son-in-law Henri Dumesnil (1823-1898), as Leonardo
Both the Johnson drawings appear, under the name of Leonardo, in the catalogue of the Dufer-Dumesnil sale, Paris, 10-12 May 1900, as lots 251 (Drapery Study of a standing Figure Facing Right, in profile) and 255 (Drapery Study of a Kneeling Figure Facing Left). Both lots were acquired by the Countess Martine Marie-Pol de Béhague.
Recent History of attribution:
In the literature, the two Johnson drapery studies shared the same attribution from 1934 until 1983; initially given by Degenhart to Fra Bartolommeo, they were subsequently attributed by almost all scholars to Leonardo. Since the pivotal Louvre exhibition of 1989-90, the previous assumption that they were all by the same hand has, however, been extensively debated. The exhibition, organised on the occasion of the museum’s acquisition of two of the draperies from the de Ganay family, to complement the four that were already in the collection, provided a unique opportunity to see together and compare all sixteen surviving drawings from this extraordinary series. The following is a summary of the subsequent published opinions regarding the attribution of the Johnson drawings (for full citations, see Literature):
David Scrase, 1990: both drawings as by Leonardo.
Keith Christiansen, 1990:
Drapery Study of a Kneeling Figure Facing Left: plausibly by Domenico Ghirlandaio;
Drapery Study of a Standing Figure Facing Right: plausibly by Andrea del Verrocchio;
Christiansen states the opinion that these studies are not the product of a single mind, but rather the work of a group of artists active in Verrocchio’s workshop in the late 1460s and 1470s. On stylistic grounds, he links the Drapery Study of a Kneeling Figure Facing Left with a drapery study in Berlin (Louvre/Viatte no. 9), which he relates to the seated figure of St. Matthew in Ghirlandaio’s Santa Fina chapel vault fresco, in the Collegiata at San Gimignano. The Drapery Study of a Standing Figure Facing Right, and also five or six of the other drapery studies in the group (Louvre/Viatte nos. 4, 10, 12, 13, 15 and possibly 14), Christiansen attributes to Verrocchio himself, associating the drawings with the artist’s planning of the figure of the resurrected Christ in his bronze group of Christ and Saint Thomas, begun in 1467, for Orsanmichele, Florence;
David Alan Brown, 1998: both drawings as ‘Workshop of Verrocchio’.
Brown states that the whole idea of assigning the drapery studies to individual artists remains problematic, preferring to consider them the product of a collective effort, subject to the discipline of a studio.
Pietro C. Marani, 1999: both drawings as ‘Workshop of Verrocchio’.
Marani also sees these studies as the work of a group of artists within Verrocchio’s workshop, and stresses the impossibility of distinguishing Leonardo’s hand within the group of drawings.
Françoise Viatte, 2003: both drawings as Leonardo
In her essay, ‘The early drapery studies’, in the catalogue of the major Leonardo exhibition at the Metropolitan Museum of Art, New York, Viatte acknowledged that the 1989-90 exhibition at the Louvre and the juxtaposition of the sixteen drapery studies had led to intense reconsideration of their nature, date, and attribution. Despite this, she reaffirmed her opinion, as presented in 1989, that all the drawings in the group are by Leonardo. The essay also provides a very useful, more detailed account of the various scholarly opinions that have been expressed since 1989.
Carmen Bambach, 2004:
Drapery Study of a Kneeling Figure Facing Left, as Verrocchio.
1. G. Vasari, Le Vite de più eccellenti Pittori Scultori ed Architettori, vol. III, ed. Milanesi, Florence 1878, pp. 357-58
2. Six in the Louvre, including two acquired from the de Ganay family (one a gift in 1989 and the other a purchase), inv. nos. 2256, RF 41904, RF 41905, RF 1081, RF 1082, 2255 ; one in the Lugt Collection, Fondation Custodia, Paris, inv. no. 6632, offered to Frits Lugt in 1954 by the Marquis de Ganay in memory of the Comtesse de Béhague; one in the Musée des Beaux-Arts, Rennes, inv. no. 794-1-2507; three in the Uffizi, inv. nos. 420E, 437E, 433E; one in the British Museum, inv. no. 1895-9-15-489.
Two other drawings in Berlin, Staatlische Museen, inv. no. 5039 and Rennes, inv. no. 794-1-2506, were associated with the previous group in the exhibition of 1989 (Viatte nos. 9, 13)
3. G. Vasari, Lives of the Painters, Sculptors and Architects…., trans. G. du C. de Vere, vol. I, London 1996, p. 626
4. Musée du Louvre, inv. no. 2255
5. C. Bambach, ‘Leonardo and drapery studies on ‘tela sottilissima di lino’, Apollo, January 2004, p. 45 and pp. 49-50
6. London, British Museum, inv. no. 1895-9-15-489; F. Viatte, Leonard de Vinci. Les études de draperie, exhib. cat., Paris, Musée du Louvre 1989-1990, p. 56, no. 7, reproduced p. 57
7. Paris, Musèe du Louvre, inv. no. RF 1082; Viatte, op. cit., 1989-1990, p. 66, no. 12, reproduced p. 67
8. C. Bambach, op. cit., 2004, p. 48
9. London, British Museum, Florence, Galleria degli Uffizi, Fra Angelico to Leonardo. Italian Renaissance Drawings, exhib. cat., 2010-2011, under no. 89, p. 284
10. A.E. Popham, The Drawings of Leonardo da Vinci, London 1946, p. 35
11. C. Bambach, op. cit., 2004, p. 44
12. Vasari in his life of Verocchio seems to mention only a few of the artists which were in his bottega namely: Pietro Perugino, Leonardo da Vinci, Francesco di Simone Fiorentino, Agnolo di Polo and Lorenzo di Credi. See G. Vasari, op. cit., vol. III, ed. Milanesi, Florence 1978, pp. 371-72. Vasari does not include for example: Ghirlandaio, Biagio d’Antonio, Botticini and Cosimo Rosselli, who are know also to have been there
13. B. Py, op. cit., 2001
14. B. Py, op. cit.,2001, p. 270
15. B. Py, op. cit., 2001, p. 17
16. F. Viatte, op. cit., 2000, pp. 117-18; C. Bambach, op. cit., 2004, p. 47
17. B. Py, op. cit., 2001
18. B. Py, op. cit., 2007, p. 7