The Guardian reminds us that the last time a Rubens was “rediscovered” the buyer paid £49.5m for it–and that was for a painting of a brutal massacre. How much do they think the beautiful Spanish lady will go for?

Who the lady with the determined chin is, why the most famous painter of her day never finished her portrait, and where she has been hanging for most of the last 400 years, remain mysterious – but she is now valued at up to £6m, as a previously unrecorded work by Rubens.

“It’s a fascinating piece precisely because it is unfinished, so she seems to step into life out of nothingness,” said Alex Bell, an expert on old master paintings at Sotheby’s, where the painting will be auctioned next week. “Although the face and the hand are finished, you can see how he sketches in the ruff and details of the costume by dragging the paint quickly across the canvas – it gives you a wonderfully immediate feeling of how he worked.”

Rubens leaves a 400-year-old mystery – and a painting worth up to £6m (Guardian)