25 March, the Feast of the Annunciation, commemorates the  appearance of  the Archangel Gabriel to the Virgin Mary to announce that she would conceive a son, Jesus, by the power of the Holy Spirit.  This event has been depicted in numerous illustratons which often incorporate lilies, Lilium candidum, in reference to Mary’s chastity.  The example here is by the Master of the Judgement of Paris, who worked in Florence from c. 1430 until c. 1450; now in the Courtauld Gallery, London.