stylistic:tone
Rome and France (1513–1519)

In March 1513, Lorenzo de' Medici's son Giovanni assumed the papacy (as Leo X); Leonardo went to Rome that September, where he was received by the pope's brother Giuliano. From September 1513 to 1516, Leonardo spent much of his time living in the Belvedere Courtyard in the Apostolic Palace, where Michelangelo and Raphael were both active. Leonardo was given an allowance of 33 ducats a month and, according to Vasari, decorated a lizard with scales dipped in quicksilver. The pope gave him a painting commission of unknown subject matter, but cancelled it when the artist set about developing a new kind of varnish. Leonardo became ill, in what may have been the first of multiple strokes leading to his death. He practised botany in the Vatican Gardens, and was commissioned to make plans for the Pope's proposed draining of the Pontine Marshes. He also dissected cadavers, making notes for a treatise on vocal cords; these he gave to an official in hopes of regaining the Pope's favour, but he was unsuccessful.

In October 1515, King Francis I of France recaptured Milan. On 21 March 1516 Antonio Maria Pallavicini, the French ambassador to the Holy See, received a letter sent from Lyon a week previously by the royal advisor Guillaume Gouffier, seigneur de Bonnivet, containing the French king's instructions to assist Leonardo in his relocation to France and to inform the artist that the King was eagerly awaiting his arrival. Pallavicini was also asked to reassure Leonardo that he would be well received at court, both by the King and by his mother, Louise of Savoy. Leonardo entered Francis's service later that year, and was given the use of the manor house Clos Lucé near the King's residence at the royal Château d'Amboise. He was frequently visited by Francis, and drew plans for an immense castle town the King intended to erect at Romorantin. He also made a mechanical lion, which during a pageant walked towards the King and – upon being struck by a wand – opened its chest to reveal a cluster of lilies.

Leonardo was accompanied during this time by his friend and apprentice Francesco Melzi, and was supported by a pension totalling 10,000 scudi. At some point, Melzi drew a portrait of Leonardo; the only others known from his lifetime were a sketch by an unknown assistant on the back of one of Leonardo's studies (c. 1517) and a drawing by Giovanni Ambrogio Figino depicting an elderly Leonardo with his right arm wrapped in clothing. The latter, in addition to the record of an October 1517 visit by Louis d'Aragon, confirms an account of Leonardo's right hand being paralytic when he was 65, which may indicate why he left works such as the Mona Lisa unfinished. He continued to work at some capacity until eventually becoming ill and bedridden for several months.