A study for a fresco of the late 1560s painted for the Palazzo Battista Grimaldi, now in the Palazzo Bianco, Genoa, B. Suida Manning and W. Suida, Luca Cambiaso, la vita et le opere, Milan, 1958, p. 71, fig. 273. The old inscription on this study suggests that Orazio, rather than his father Luca, was responsible for the design of the fresco.
The attribution is supported by Mary Newcome Schleier who compares the present drawing to one sold at Christie's, Rome, 7 November 1989, lot 473, illustrated.