Prior to the reemergence of this drawing in 2003, the composition was only known through a copy attributed to Francesco Bartolozzi, in the Royal Collection, Windsor Castle.1 Both the present drawing and the Bartolozzi copy also correspond very closely, albeit in reverse, to an etching, by Bartolozzi, inevitably after Guercino (fig.1).
The present drawing can be dated, on stylistic grounds, to the late 1630s. The theme of Sibyls, often shown writing down their prophecies or contemplating their texts, is familiar from many of Guercino's most celebrated paintings from the next decade of his career, perhaps most notably his famous Persian Sibyl, in the Pinacoteca Palatina, Rome.2
The pose and expression of the Sibyl, coupled with Guercino's characteristically measured yet energetic handling, captures an almost ethereal state of deep engagement with the text that she is studying. This sense of contemplation is further accentuated as she rests her forehead on one hand.
Nicholas Turner confirmed the attribution to Guercino prior to the 2003 sale.
1. D. Mahon and N. Turner, The Drawings of Guercino in the collection of Her Majesty the Queen at Windsor Castle, Cambridge 1989, p. 173, no. 592
2. N. Turner, The Paintings of Guercino, Rome 2017, p. 630, no. 336, reproduced