What is the most characteristic element of a Salvator Mundi, the archetypal image of Christ as Saviour of the World? It is Christ’s right hand raised in blessing. The left hand cradling an orb completes the type, which was fashionable in north-eastern Italy from around 1500, originating in Northern Europe. But now, two very different kinds of examination of Leonardo’s enigmatic picture, which sold for $450m at Christie’s New York in 2017 and is now owned by the Saudi Arabian culture ministry, suggest that this “ Salvator Mundi” was initially conceived as just a head and shoulders, with the hands and arms added later on. One analysis was conducted by the Louvre’s experts, when Saudi Arabia’s Ministry of Culture permitted detailed scientific analysis of its picture in 2018; the other was conducted by a computer scientist and an art historian, and has just been accepted for publication in The MIT Press’s