Moses stands on the left, his hand raised as he beckons people to gaze upon the bronze serpent coiled around the pole held by Eleazar, a priest. The scene is taken from the Old Testament: God had sent a plague of 'fiery serpents' to punish the Israelites for their sinfulness and lack of faith (Numbers 21: 6), but anyone who followed Moses' instruction would be protected.
While some try to struggle out of the grips of the snakes, one figure - a woman in the black dress at the centre of the group - stares intently at the bronze serpent and so remains unharmed. She is probably based on Rubens's second wife, Hélène Fourment.
Rubens made this picture with the help of some of his studio assistants. They may have used a modello (a sketch used as a guide for a painting) to block out the composition before Rubens painted in the details.
Credit: Bought, 1837