For centuries, the provenance of art was traditionally recorded only if it added cachet to the art itself. If a painting was once in the collection of a Pope, a King or a famous collector, that was worth recording. Anything else was not. Until the 1990’s, auction and dealers’ sale catalogues rarely included any provenance, unless it was special. In the last 25 years, there has been a radical shift: good provenance has become critical.