'Paris, son of the Trojan King Priam, who was living as a shepherd, was sought out by Mercury, the messenger of the gods, and asked to decide which of the three goddesses, Venus, Juno or Minerva, was the most beautiful. Paris chose Venus, who rewarded him with the beautiful Helen, wife of the Spartan King Menelaus. Paris's abduction of Helen led to the downfall of Troy. The story told in Dares of Phrygia's sixth-century Bellum Troianum was modified in later accounts, such as the influential Historia destructionis Troiae by Guido delle Colonne in the thirteenth century. In Guido's version, Paris is a knight out hunting who, tying his horse to a tree, fell asleep and dreamed that Mercury presented the three goddesses to him; Paris asked them to put aside their clothes, and when he chose Venus he was released from sleep. Cranach seems to follow this version here; his knight is lost in the forest and has a dazed appearance, as if awakening from a dream.
Cranach has painted Mercury as an old man who hands him a crystal orb which is inscribed 'MONET' ('he (or it) warns or advises' in Latin), perhaps referring to Paris's task of judging the three goddesses in front of him. As in other versions by Cranach, the goddesses are hard to identify, but it is probably Venus who stands closest to Paris, casting a knowing look at the viewer and at whom Cupid aims his arrow.'
[http://www.royalcollection.org.uk/eGallery/object.asp?searchText=cranach&x=0&y=0&object=405757&row=4&detail=about] (accessed 23.02.2012)