This lecture was given during the exhibition 'The Miracle in the Snow. Pieter Bruegel the Elder' at the Oskar Reinhart Collection ‘Am Römerholz’ Winterthur, 23 November 2019-1 March 2020. It tackles the question of authenticity, given the fact that Bruegel's Adoration of the Kings in the Snow was copied multiple times by his elder son, Pieter Brueghel the Younger. To this end, the painting is examined from the point of view of its techniques and materials as well as its sublime pictorial style. Seemingly effortless, Bruegel was in fact an inveterate planner and did much more preparation for the composition than is seen at first glance. Surprisingly, the copies provide clues about the creative process of the original version.