The catalogue of the early works of Jacopo Tintoretto has been seriously distorted by the accretion of paintings by later associates and followers. Among them is Giovanni Galizzi, a Bergamasque active in Venice from 1543 to 1565. By folio following a chain of connections from his two signed and dated altarpieces, some twenty works previously attributed to Tintoretto can be assigned to Giovanni. Almost all his paintings after 1550 are based upon prototypes by Tintoretto and show signs of the kind of collaboration that could have occurred only in a large and busy shop, indicating that Giovanni worked in Tintoretto's studio itself. Among Giovanni's collaborators was the Flemish Marten de Vos, reported to have been present in Tintoretto's shop in the early 1550s.