Sir Denis Mahon and Nicholas Turner have kindly confirmed the attribution on examining the original. The drawing is probably connected to the Bathsheba, now lost, painted by Guercino for Conte Astorre Hercolani in 1640. Guercino's account book records that on 23 August 1640 he received 375 scudi for the picture (B. Ghelfi, Il libro dei conti del Guercino, Bologna, 1997, p. 102, no. 224).
The final composition for the Bathsheba, in which she is shown seated with two attendants to the right, is known through an old copy formerly in the Perticari Collection, Pesaro (N. Grimaldi, Il Guercino, Bologna, 1968, pl. 185). In the Perticari picture one of the attendants wears a turban and a low-cut bodice with a plunging neckline reminiscent of the attendant's in the present drawing. Preliminary drawings for the picture, in which Guercino moves towards the final composition, are in the Weld-Blundell Collection at the Walker Art Gallery, Liverpool (X. Brooke, Mantegna to Rubens, The Weld-Blundell Drawings Collection, London, 1998, no. 32) and The Royal Library, Windsor Castle (D. Mahon and N. Turner, The Drawings of Guercino at Windsor Castle, Cambridge, 1989, no. 430, as School but perhaps a retouched original).
A drawing by Guercino formerly with Hazlitt, Gooden and Fox (European Drawings, Recent Acquisitions, London, 1988, no. 28) may also be associated with the present drawing. Bathsheba is shown seated in profile to the left and only partially covered by a billowing cloth. Three lines of pen and brown ink sketched under the left arm in that study indicate the right hand held across her chest, a development fully realised in the present drawing.
We are grateful to Sir Denis Mahon and Nicholas Turner for their help in preparing this note.