It obviously hasn’t been sitting in a bank vault for 500 years but that’s where it was found. They had always had the sketch. Now they have the painting that came with it.

After seeing the drawing he produced, the marquesa wrote to the artist, imploring him to produce a full-blown painting.

But shortly afterwards he embarked on one of his largest works, The Battle of Anghiari on the walls of Florence’s town hall, and then, in 1503, started working on the Mona Lisa.

Art historians had long believed he simply ran out of time — or lost interest — in completing the commission for Isabella d’Este.

Now it appears that he did in fact manage to finish the project — perhaps when he encountered the aristocrat, one of the most influential female figures of her day, in Rome in 1514.

Whatever, whenever, it is an amazing picture and even in profile she does have that smile.