The Mona Lisa Foundation

The ‘Heidelberg Document’

In 2005, reports emerged concerning a great discovery made at Heidelberg University. There, the German scholar Armin Schlechter, while researching some old documents during a cataloguing procedure, stumbled upon an annotation in the margin of a letter written by Cicero in the 1st Century B.C. A collection of Cicero’s letters, Epistulae ad familiares, had been published in Bologna in 1477.

The handwritten comment, dated 1503, by Agostino Vespucci in the margin of one of Cicero’s letters. Vespucci has witnessed Leonardo working on a portrait of Lisa del Giocondo, and also remarks about the ‘Battle of Anghiari’ commission.

The hand-written comment, dated October 1503, by Agostino Vespucci in the margin of one of Cicero’s letters. Vespucci has witnessed Leonardo starting the portrait of Lisa del Giocondo, and also remarks about the ‘Battle of Anghiari’ commission.

The painter Apelles. In this way Leonardo da Vinci makes it in all his paintings, for example the head of Lisa del Giocondo and of Anne, the mother of the Virgin. We will see what he is going to do with regard to the hall of the Great Council about which he has just agreed with the Gonfaloniere.” October 1503

Apelles pictor. Ita Leonardus uincius facit in omnibus suis picturis, ut enim Caput lise del giocondo et anne matris uirginis. videbimus quid faciet de aula magni consilii, de qua re convenit iam cum vexillofero.” 1503.

This note in the margin of the letter was handwritten by Agostino Vespucci, a secretary and assistant to Niccolò Machiavelli, the Second Chancellor of the Signoria of Florence, and is a powerful piece of evidence regarding the ‘Mona Lisa’. There is at this time a close friendship between Niccolò and Leonardo, and so of course Niccolò’s secretary was well aware of all the connections.

Vespucci highlights the relevance of the following section of Cicero’s text:

Nunc ut Appelles Veneris caput & summa pectoris politissima arte perfecit: reliquam partem corporis incohatam reliquit…

Apelles perfected the head and bust of his Venus with the most elaborate art, but left the rest of her body in the rough [inchoate]…

Clearly, Cicero’s text deals not only with the exquisite art of Apelles, but with his habit of deliberately leaving work unfinished. Dr. Jill Burke of the University of Edinburgh, wrote (in the Leonardo Da Vinci Society Newsletter, Issue 30, May 2008) that: “ … the insight it [the document] gives us into perceptions of finish in early ‘cinquecento’ painting … It could be that the fashion for the display of drawings and unfinished works in Florence in the early sixteenth century was perceived by some of the educated elite, such as Vespucci, as referring to the practice of Apelles as noted by Cicero. In other words, leaving works ‘unfinished’ could in itself be taken as a sign of artistry.

The document, considered absolutely reliable by scholars, brings up many critical points:

  • It firmly establishes that by October 1503 Leonardo was working on Lisa’s portrait. Vespucci refers to “… the head of Lisa …”, but it was once common terminology for the subject of a portrait to be having ‘their head painted’. Furthermore, most portrait artists would use the head as the starting point of the picture. (Vasari’s text refers to a portrait of Lisa, not just a head).
  • It also re-establishes the close ties between Leonardo and Machiavelli and his staff.
  • Vespucci’s note, and the appended date, confirm that in this matter at least, Vasari was absolutely correct in stating that Leonardo did paint the portrait of Lisa del Giocondo shortly after his return to Florence.
  • Vespucci makes here a short but distinct connection between the del Giocondo portrait and the major commission of the ‘Battle of Anghiari’ fresco, which Leonardo had not yet started. This leads to suggestions that Machiavelli may have used influence to help Leonardo get these commissions, particularly the one from the government.
  • It suggests that the portrait of Lisa del Giocondo was intentionally left unfinished.
  • At around this time in 1503, Machiavelli was away on one of his diplomatic missions, this time in Rome. His wife had just given birth to their son, and a good friend Luca Ugolini, wrote to him:
    Dearest friend, hail! Truly your Mona Marietta has not deceived you, for he is your spit and image: Leonardo da Vinci could not have painted a better portrait.”

    Influential Florentines were well aware that Leonardo was back in town, and working. In a way, the Heidelberg Document encapsulates a snapshot at a point in Leonardo’s life; his circle of contacts, and the way they are interconnected. Here, for example, Vespucci’s familiarity with Leonardo’s activities is inscribed: Vespucci’s superior, Machiavelli, who Leonardo met the previous year, is now the second most important official in the Florentine government (Signoria). Machiavelli knows the del Giocondo family, plus he is instrumental in securing the fresco commission from the Signoria for Leonardo. Then, it is Vespucci who later describes the history of the Battle of Anghiari in writing for Leonardo, so that the artist will have a context for the design.

    Page from Cicero’s Epistulae ad Familiares, on which Agostino Vespucci referred to Leonardo working on the portrait of Lisa del Giocondo.

    Agostino Vespucci was the only known eye- witness to have recorded Leonardo painting the portrait of Lisa del Giocondo.


    Apelles has long been considered the greatest painter in Greek antiquity. When Vespucci noticed the name in Cicero’s text, he impulsively related it to Leonardo, with whom he was now in frequent contact. The connection between the artists is that both had the reputation of starting a portrait with the head and shoulders of the subject, and rendering it in extraordinary detail, before continuing with the rest of the painting, often deliberately leaving some parts unfinished.

    With this remark, Vespucci is likely telling us in effect that in his Mona Lisa, Leonardo certainly painted all the details of the face – subsequently the hands and other parts also; and typically left other sections either unfinished or to his assistants to finish.

    The Louvre Reaction

    The response by the Louvre to the discovery of this document was as follows:

    Léonard de Vinci était en train de peindre en 1503 le portrait d’une dame florentine qui s’appelle Lisa del Giocondo. De ça désormais on en est certain. Malheureusement, on a pas de certitude absolue que ce portrait de Lisa del Giocondo soit le tableaux du Louvre.

    Leonardo da Vinci was painting, in 1503, the portrait of a Florentine lady by the name of Lisa del Giocondo. About that we are now certain. Unfortunately, we cannot be absolutely certain that this portrait of Lisa del Giocondo is the painting of the Louvre.
    Vincent Delieuvin, Curator at the Louvre, 2005

    This statement makes it clear that the Louvre is open to the idea of there being another painting of Mona Lisa by Leonardo da Vinci.


    Agostino Vespucci

    Augustino Matthei de Vespuccis de Terrenova: the honorific title was added in honour of the voyages of his cousin, Amerigo Vespucci, the famous navigator, cartographer and explorer. Amerigo’s patron was none other than Lorenzo [‘The Magnificent’] di Pierfrancesco de’ Medici, who also supported Niccolò Machiavelli’s nomination to the influential Signoria position of Second Chancellor. The Vespucci family was prominent and influential in Florence, and Agostino enjoyed a relatively peaceful career as both a loyal secretary to Machiavelli, and a general civil servant to the Florentine Signoria. As such he became well acquainted with Leonardo, and played a small functionary role in assisting the great master from time to time. Similarly, both Leonardo and his father, the prominent notary Ser Piero, had numerous connections over many years with both the Vespucci family and Amerigo’s patron, Lorenzo ‘The Magnificent’. There is another notable connection: both Amerigo Vespucci and Giannetto del Giocondo, relative of Lisa’s husband Francesco, had considerable business interests in Lisbon.

    Amerigo Vespucci, the great explorer and relative of Agostino Vespucci, Machiavelli’s assistant