Thought to be Leonardo da Vinci’s earliest complete work, it was painted between 1473 and 1475. The painting shows the dramatic meeting between the archangel Gabriel and Mary when he tells her that she has been chosen to conceive the son of God. There are several references to Christian iconography, including the lily in Gabriel’s hand, symbolising fertility, and the walled garden – a fecund space shielded from the outside world – representing Mary’s virginity. The Annunciation showcases Da Vinci’s use of geometrics to guide our eye to key elements of the composition, such as the river port in the background, which is veiled in a delicate, mysterious haze thanks to sfumato, a painting technique that the artist eventually mastered.