Simon accumulated a significant private art collection which included works of the Impressionists, Old Masters, modern and native art. In the 1960s, he spent $6 million on artworks – an inventory of slightly less than 800 objects – and real estate – a building at 18 East 79th Street – from the Duveen Gallery in Manhattan, which specialized in old masters. Scholars including the critic Clement Greenberg and the Metropolitan Museum of Art curator Theodore Rousseau studied the Duveen purchases for Simon and were able to identify numerous misattributions. Simon ended up selling much of the collection and only kept around 130 objects, primarily paintings, a handful of sculptures, a few porcelains, and a cape purportedly worn by Charles IV of Spain. However, his collection holds three autographed Rembrandt paintings, considered highly important works of Rembrandt in Southern California.
The looting and illicit export of art treasures is not a new problem. It’s happened whenever there have been armed conflicts during which victorious troops plundered churches, temples and other buildings. Germany carried out massive looting in World War II. By the start of the 21st Century the trade in illicit antiquities had become so huge it was worth billions of dollars each year and was the biggest international crime outside drug and arms trafficking according to The New York Times. When a piece is stolen, the consequence for scholars is tragic, because essential information about the piece – where it was found, what else was with it – is lost forever.