The work depicts John the Baptist in isolation. Through the use of chiaroscuro, the figure appears to emerge from the shadowy background. The saint is dressed in pelts, has long curly hair and is smiling in an enigmatic manner reminiscent of Leonardo's famous Mona Lisa. He holds a reed cross in his left hand while his right handpoints up toward heaven like that of Saint Anne in Leonardo's Burlington House Cartoon. According to Frank Zöllner, Leonardo's use of sfumato "conveys the religious content of the picture," and that "the gentle shadows imbue the subject's skin tones with a very soft, delicate appearance, almost androgynous in its effect, which has led to this portrayal being interpreted as an expression of Leonardo's homoerotic leanings." Kenneth Clark claimed that for Leonardo, Saint John represented "the eternal question mark, the enigma of creation", and noted the sense of "uneasiness" that the painting imbues. Barolsky adds that: "Describing Saint John emerging from the darkness in almost shockingly immediate relation to the beholder, Leonardo magnifies the very ambiguity between spirit and flesh. The grace of Leonardo's figure, which has a disturbingly erotic charge, nonetheless conveys a spiritual meaning to which Saint John refers when he speaks of the fullness of grace from God."
Dating
The dating of Saint John the Baptist is disputed. It was seen by Antonio de Beatis in Leonardo's workshop at Clos Lucé; his diary entry giving a of 17October 1517. Traditionally the painting has been considered the artist's last and dated to 1513–1516; Leonardo's sfumato technique here being considered to have reached its apogee. Some experts, however, have compared the hand of Saint John to a similar work by a pupil in the Codex Atlanticus, dating the commencement of the picture to around 1509. The pose is also similar to that of a sculpture of the same subject completed after 1510 for the Florence Baptistery by Giovanni Francesco Rustici. Leonardo is thought to have given Rustici technical advice for his commission; it is possible that one artist could have influenced the other with the idea for the pose.
Prior to this work, Saint John had traditionally been portrayed as a gaunt ascetic. Leonardo's innovative depiction proved influential upon Raphael's workshop; several portraits of Saint John painted around 1517–18 attributed to Raphael and Giulio Romano show a similarly youthful saint in isolation, with a strong contrast between the dark background and the illumination of the figure. Numerous copies and variations of Saint John the Baptist made by Leonardeschi exist.
