Rembrandt had several pupils who naturally produced copies of his works, notably Jacob Backer, G. van Vliet, Pieter Verelst, C. Paudiss, Van der Eeckhout, S. van Hoogstraten, Aart van Gelder or Constantin Renesse.
Govaert Flinck also imitated Rembrandt as well as Murillo or Ferdinand Bol, one of his most talented disciples, whose ink drawings were often sold as by Rembrandt. Other imitators of the Dutch master were Philip de Kooning, Karel Fabritius, Jan Victors, Jan Lievens, who also copied Van Dyck, Cornelis van Haarlem, Heyman Dulaert, Salomon Koninck and later C. W Dietrich who also copied Alexander Thiele, van Ostade, Berghem, Ruysdael, Karel Dujardin, Salvator Rosa and Watteau.
There are many works by Dietrich now in the Dresden Gallery, which were previously attributed to other great masters.
A. de Vries, W. de Poorter, A. Verdoel, H. Heerschop, J.Ovens, Willem Drost or Nicholas Maes also copied Rembrandt.
These copies were produced during the 17th and 18th centuries but others are quite modern like a self-portrait in the Museum of Kassel. In addition there are hundreds of faked drawings attributed to Rembrandt throughout the world.
But there are also genuine works that have been retouched or transformed. For instance, Rembrandt's «Lesson of Anatomy» had been badly damaged in a fire and what had remained of it was later found in England though quite rearranged by an unscrupulous restorer.
Many forged Rembrandt works also appeared in some major exhibitions, notably in Amsterdam and Rotterdam in 1956 such as «The Painter in his studio» from the Museum of Fine Arts in Boston, «Young Girl in a local costume» from a collection in Cleveland, «The Studio» from the Glasgow Museum, «The Holy Family» from the Ludlow Collection, a landscape from the Montreal Museum, a «Monk reading» from the Museum of Helsinki, «Ann and Tobias», «The fight between Jacob and the Angel», «St John the Evangelist», all from the Boston Museum and Saint Bartholomew the Apostle, a fake produced during the 19th Century.