A study for God the Father in the upper register of the Annunciation in the Cappella delle Tre Figure in the Church of the Servi, Siena, F. Sricchia Santoro, L'arte a Siena sotto i Medici, exhib. cat., Palazzo Pubblico, Siena, 1980, no. 49, illustrated. The chapel was sold in 1531 to Alfonso Valeri on the condition that he would commission a painting of the Annunciation for the altarpiece. By 1586 the contract was not yet fulfilled and the chapel was sold to Virgilio Cancelli who was obliged to spend 100 scudi on an altarpiece. Cancelli probably immediately commissioned the painting from one of the foremost painters in Siena, Francesco Vanni. Vanni later re-used this drawing for the figure of God the Father in the altarpiece of the Immaculate Conception in the church at Montalcino, signed and dated 1588, F. Sricchia Santoro, op. cit., no. 48, illustrated. The two figures are similar even in the smallest details, like the bent thumb of the left hand of God or His gaze to the left. The Siena painting must pre-date the Montalcino one: the direction in which God is looking is part of the narrative as the Virgin, after having listened to the Archangel, looks towards Him. In the later painting God looks in the same direction, but without thought for the narrative. Vanni evidently wanted to save effort by re-using preparatory studies from previous paintings, perhaps because the commission came from a provincial church where the expectations of the patron were lower.
The drawing can, therefore, be dated between the commission of the Annunciation in 1586 and 1588, when the Montalcino altarpiece was finished.