Question: At what point in time did the Rembrandt Research Project star?
About the article "Rembrandt", section "Expert assessments".

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The first western scholar to discuss the painting was Wilhelm von Bode who in his "History of Dutch Painting" (1883) stated that it was a Rembrandt dating from his "late" period, that is, 1654.
Somewhat later, Abraham Bredius examined the picture quite closely and had no doubts that its author was Rembrandt.
At the beginning of the twentieth century, Alfred von Wurzbach suggested that Rembrandt's student, Aart de Gelder might have been the author, but his opinion was generally disregarded.
Throughout most of the twentieth century, there was general agreement that the painting was indeed by Rembrandt and even Julius S. Held, who at one time questioned its Polish connection, never doubted Rembrandt's authorship.
However, in 1984, Josua Bruyn, then a member of the Rembrandt Research Project (RRP) tentatively suggested that certain characteristics of the work of Willem Drost, another student of Rembrandt, could be observed in the painting.
Though the mysterious and somewhat solemn expression on the Rider's brilliantly painted face point to Rembrandt,"The Polish Rider" is unlike Rembrandt's other work in certain other ways.
In particular, Rembrandt rarely worked on equestrian paintings, the only other known equestrian portrait in Rembrandt's work being the "Portrait of Frederick Rihel", 1663 (National Gallery, London).
But Bruyn's remained a minority opinion, the suggestion of Drost's authorship is now generally rejected, and the Frick itself never changed its own attribution, the label still reading "Rembrandt" and not "attributed to" or "school of".
More recent opinion has shifted even more decisively in favor of the Frick, with Simon Schama in his 1999 book "Rembrandt's Eyes", and a Rembrandt Project scholar, Ernst van de Wetering (Melbourne Symposium, 1997) both arguing for attribution to the master.
Those few scholars who still question Rembrandt's authorship feel that the execution is uneven, and favour different attributions for different parts of the work.
A 1998 study published by the RRP concluded that another artist's hand, besides that of Rembrandt, was involved in the work.
Rembrandt may have started the painting in the 1650s, but perhaps he left it unfinished and it may have been completed by someone else. 
The Rembrandt Research Project (RPP) is an initiative of the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), which is the Netherlands Organization for Scientific Research.
Its purpose is to organize and categorize research on Rembrandt, with the aim of discovering new facts about this Dutch Golden Age painter and his studio.
The project was started in 1968, but has since become the authority on Rembrandt and has final say in whether a painting is "genuine". 
In 1968 the Rembrandt Research Project began under the sponsorship of the Netherlands Organization for the Advancement of Scientific Research; it was initially expected to last a highly optimistic ten years.
Art historians teamed up with experts from other fields to reassess the authenticity of works attributed to Rembrandt, using all methods available, including state-of-the-art technical diagnostics, and to compile a complete new catalogue raisonné of his paintings.
As a result of their findings, many paintings that were previously attributed to Rembrandt have been removed from their list, although others have been added back.
Many of those removed are now thought to be the work of his students.
One example of activity is "The Polish Rider", in New York's Frick Collection.
Rembrandt's authorship had been questioned by at least one scholar, Alfred von Wurzbach, at the beginning of the twentieth century, but for many decades later most scholars, including the foremost authority writing in English, Julius S. Held, agreed that it was indeed by the master.
In the 1980s, however, Dr. Josua Bruyn of the Foundation Rembrandt Research Project, cautiously and tentatively attributed the painting to one of Rembrandt's closest and most talented pupils, Willem Drost, about whom little is known.
But Bruyn's remained a minority opinion, the suggestion of Drost's authorship is now generally rejected, and the Frick itself never changed its own attribution, the label still reading "Rembrandt" and not "attributed to" or "school of".
More recent opinion has shifted even more decisively in favor of the Frick, with Simon Schama in his 1999 book "Rembrandt's Eyes", and a Rembrandt Project scholar, Ernst van de Wetering (Melbourne Symposium, 1997) both arguing for attribution to the master.
Those few scholars who still question Rembrandt's authorship feel that the execution is uneven, and favour different attributions for different parts of the work.
A similar issue was raised by Simon Schama in his book "Rembrandt's Eye" concerning the verification of titles associated with the subject matter depicted in Rembrandt's works.
For example, the exact subject being portrayed in "Aristotle with a Bust of Homer" (recently retitled by curators at the Metropolitan Museum) has been directly challenged by Schama applying the scholarship of Paul Crenshaw.
Schama presents a substantial argument that it was the famous ancient Greek painter Apelles who is depicted in contemplation by Rembrandt and not Aristotle.
Another painting, "Pilate Washing His Hands", is also of questionable attribution.
Critical opinion of this picture has varied since 1905, when Wilhelm von Bode described it as "a somewhat abnormal work" by Rembrandt.
Scholars have since dated the painting to the 1660s and assigned it to an anonymous pupil, possibly Aert de Gelder.
The composition bears superficial resemblance to mature works by Rembrandt but lacks the master's command of illumination and modeling.
The attribution and re-attribution work is ongoing.
In 2005 four oil paintings previously attributed to Rembrandt's students were reclassified as the work of Rembrandt himself: "Study of an Old Man in Profile" and "Study of an Old Man with a Beard" from a US private collection, "Study of a Weeping Woman", owned by the Detroit Institute of Arts, and "Portrait of an Elderly Woman in a White Bonnet", painted in 1640.
Rembrandt's own studio practice is a major factor in the difficulty of attribution, since, like many masters before him, he encouraged his students to copy his paintings, sometimes finishing or retouching them to be sold as originals, and sometimes selling them as authorized copies.
Additionally, his style proved easy enough for his most talented students to emulate.
Further complicating matters is the uneven quality of some of Rembrandt's own work, and his frequent stylistic evolutions and experiments.
As well, there were later imitations of his work, and restorations which so seriously damaged the original works that they are no longer recognizable.
It is highly likely that there will never be universal agreement as to what does and what does not constitute a genuine Rembrandt.
In a letter to Huygens, Rembrandt offered the only surviving explanation of what he sought to achieve through his art: "the greatest and most natural movement", translated from "de meeste en de natuurlijkste beweegelijkheid".
The word "beweechgelickhijt" is also argued to mean "emotion" or "motive."
Whether this refers to objectives, material or otherwise is open to interpretation; either way, critics have drawn particular attention to the way Rembrandt seamlessly melded the earthly and spiritual.
Earlier 20th century connoisseurs claimed Rembrandt had produced over 600 paintings, nearly 400 etchings and 2,000 drawings.
More recent scholarship, from the 1960s to the present day (led by the Rembrandt Research Project), often controversially, has winnowed his oeuvre to nearer 300 paintings.
His prints, traditionally all called etchings, although many are produced in whole or part by engraving and sometimes drypoint, have a much more stable total of slightly under 300.
It is likely Rembrandt made many more drawings in his lifetime than 2,000, but those extant are more rare than presumed.
Two experts claim that the number of drawings whose autograph status can be regarded as effectively "certain" is no higher than about 75, although this is disputed.
The list was to be unveiled at a scholarly meeting in February 2010.
At one time about ninety paintings were counted as Rembrandt self-portraits, but it is now known that he had his students copy his own self-portraits as part of their training.
Modern scholarship has reduced the autograph count to over forty paintings, as well as a few drawings and thirty-one etchings, which include many of the most remarkable images of the group.
Some show him posing in quasi-historical fancy dress, or pulling faces at himself.
His oil paintings trace the progress from an uncertain young man, through the dapper and very successful portrait-painter of the 1630s, to the troubled but massively powerful portraits of his old age.
Together they give a remarkably clear picture of the man, his appearance and his psychological make-up, as revealed by his richly weathered face.
In his portraits and self-portraits, he angles the sitter's face in such a way that the ridge of the nose nearly always forms the line of demarcation between brightly illuminated and shadowy areas.
A Rembrandt face is a face partially eclipsed; and the nose, bright and obvious, thrusting into the riddle of halftones, serves to focus the viewer's attention upon, and to dramatize, the division between a flood of light—an overwhelming clarity—and a brooding duskiness.
In a number of biblical works, including "The Raising of the Cross", "Joseph Telling His Dreams" and "The Stoning of Saint Stephen", Rembrandt painted himself as a character in the crowd.
Durham suggests that this was because the Bible was for Rembrandt "a kind of diary, an account of moments in his own life.
"Among the more prominent characteristics of Rembrandt's work are his use of chiaroscuro, the theatrical employment of light and shadow derived from Caravaggio, or, more likely, from the Dutch Caravaggisti, but adapted for very personal means.
Also notable are his dramatic and lively presentation of subjects, devoid of the rigid formality that his contemporaries often displayed, and a deeply felt compassion for mankind, irrespective of wealth and age.
His immediate family—his wife Saskia, his son Titus and his common-law wife Hendrickje—often figured prominently in his paintings, many of which had mythical, biblical or historical themes. 
The Three Crosses is an etching and dry point painting created by Dutch artist Rembrandt van Rijn depicting the crucifixion of Jesus Christ.
The subject is Jesus Christ on the cross, flanked by the two thieves who were crucified with him.
The Virgin Mary is depicted weaping and being supported by the Evangelist.
Roman soldiers on horseback and grieving citizens are depicted around the crosses.
Professionals have speculated that the scene might be interpreted as the moment of Christ’s death.
The sky is very dark but pierced by a beam of light that surrounds the figure of Christ, representing God’s light from heaven.
The iconography in the piece is especially intricate.
According to Paul Crenshaw of the Kemper Art Museum, Rembrandt was inspired by the text from when Christ cried out, “My God, why hast thou forsaken me?” Rembrandt drew heavily on biblical sources in his work, as well as being influenced by other Baroque contemporaries.
Rembrandt created over 300 works that were inspired by the Bible.
The piece's etching does not allow for dramatic contrasts of light and shade, known as chiaroscuro.
Rembrandt produced the work in four stages, increasing in each the effects of these contrasts.
Etching and dry point are labor-intensive processes, and one of the early forms of printmaking.
Rembrandt chose these media based primarily on the fact that he was suffering from financial difficulties all the time.
He had to sell many of his etchings in order to be able to afford to print "The Three Crosses".
Rembrandt was able to make around sixty impressions from the plate in its first three stages, the darkest shadows on the piece being done in dry point, and Christ and the lighter figures being etched.
The nature of the media meant that it was possible for Rembrandt to make continuous alterations (which he did over a ten year period), adding further etching and dry point, changing the composition of the picture and making the final image darker and more chaotic: In the last stage, the Virgin Mary has become an almost disembodied head surrounded by darkness, and the figures that originally encircled her have, in consequence, been removed, as have been some of the soldiers on horseback.
A man in a large hat (also on horseback) has been added and is believed to be a figure from Rembrandt’s "The Conspiracy of Claudius Civilis."
The most dramatic alteration is to the "heavenly light" which has become considerably darkened, especially to the right of the picture, by which Rembrandt may be making a clear distinction between the 'good' and 'bad' thieves.
Each progressive change in the work increases the focal importance of the Christ figure.
In its fourth and fifth state, Rembrandt inked the plates in a different number of ways and with different qualities of ink.
One of the prints in the fourth stage is located at the Kemper Art Museum.