Have you ever wondered why, when the population of the world has skyrocketed and the overall wealth of the world has increased apace we never run out of antiques or ancient collectables? Art by old masters is a little more difficult to come by because the most valuable works are well-known and well documented. Lesser artists however can be rehabilitated, or 'rediscovered', works of student-assistants of popular artists can be reappraised or 'discovered' (reattributed) as works of the famous artist and suddenly have a value a hundred thousand or a million times the price the dealer paid. For me, who has read quite a bit about art history as it relates to dealers, auctioneers and the experts that validate the goods that they offer, the alarm bells definitely go off when a 'new' work of a famous artist is discovered, often in a 'style previously unknown' for that artist. Greed, optimism and the desire to obtain that which was previously unobtainable cause people with much money to throw caution to the wind. The great collections of famous wealthy people have in many cases been found to contain many or mostly fakes, and institutions are not invulnerable due to the fact they are spending other people's money and need star attractions, first to draw the crowds and secondly, to enhance their reputation in the world of art.
Many of these elements combined to make the Vermeer frauds possible, and not least the fact that there were virtually unlimited funds available during WWII to obtain works of art for the many museums that Hitler had planned for Germany. Buyers for Hitler, Goering, and the German government in general inflated prices in the art market all over Europe - there was a genuine boom, and inflated prices were paid for many works, enriching the art experts and dealers who validated and sold the works for hefty commissions.
Hitler had paid much more than the asking price for a genuine Vermeer, the well-known and much-loved 'The Artist in His Studio', and Goering had to have a Vermeer too, despite the tight supply. Vermeer had been 'rediscovered' some years before, his known works were in limited supply, and Han van Meegeren and the 'experts' had helped to fill that gap with the discovery of a new extended period in Vermeer's career: his Biblical Period. Goering was offered 'Christ and the Adultress' for 1.65 million guiders, the appropriate cover story and a letter of provenance was created to satisfy bureaucratic requirements that the painting was not stolen or a forced sale, expert opinion was satisfied, and the sale took place.
Meegeren's sales, usually in cash, provided a rich life for him before and during the war: he used his cash to acquire dozens of properties, and had a good supply of food and drink even in the toughest times during the war.
After the war ended van Meegeren found himself in hot water for collaboration with the enemy; i.e. dealing with Goering by selling a painting which was believed to be part of the heritage of Holland, which he solved by proving that he did not sell a genuine Vermeer but a forgery which he had created. A small jail sentence was imposed, and van Meegeren became somewhat of a folk hero in the public eye for defrauding Goering.
The final result of his efforts is felt even today, when opinions differ on certain Vermeers: are they real, are they van Meegeren, or are they a misattributed work from a previous time? The catalog of Vermeer's work has shrunk by more than half since the 19th century, net of the subsequent attribution inflation and deflation that took place during the 20th century, casting doubt on the validity of experts' opinions even before the efforts of van Meegeren which have only added to the confusion. In the art market, it's always Buyer Beware!