Of all the faces he put on canvas, Rembrandt van Rijn was fondest of the one he saw in his own mirror. Experts have identified about 60 Rembrandt self-portraits, which have been cropping up in strange places ever since the master died in 1669. Last week another of Rembrandt's self-portraits was in the news, with a typical tale of mystery attached.
The picture first came to light in London 33 years ago. An Italian nobleman, the Marchese Guido Serra di Cassano, was decorating a town house by buying wholesale lots of pictures at a few pounds apiece. Browsing about one run-down little...