Maarten de Vos's Calumny of Apelles is considered from a historical, iconographical and technical point of view. Its literary and visual sources are explored, particularly in relation to the text of Lucian, the Greek rhetorician, and to Giorgio Ghisi's engraving on the same theme. The presence of Hans van Haecht's panel-maker's mark gives 1589 as an earliest possible execution date; furthermore, stylistic resemblances with preparatory drawings by De Vos for Archduke Ernest's 1594 Joyous Entry into Antwerp suggest a late dating, probably in the last nine years of the artist's life. The technical study brings to light the original techniques and materials used in the manufacture of the panel and the application of the ground and paint layers. The pigments are mostly typical of those of the late sixteenth century and include the abundant use of smalt, which explains why certain draperies have lost their colour. The study also uncovers two major modifications that were carried out after the painting was complete: the addition of Calumny's jewelled bodice and that of the top plank. Calumny's new luxurious bodice drew attention to her worldly qualities and was most likely added between 1750 and 1850, while the extra board at the top was probably added earlier, giving the composition a more modern spatial structure.