Corneille de Lyon

In 1564 Catherine de' Medici, the queen mother of France, called on a painter in Lyon and found her own portrait among his stock. She was struck by how alive it looked. The painter was Corneille de La Haye, known simply as Corneille de Lyon after the city where he spent his career, though he had come from The Hague in the Low Countries.

He specialised in something very particular: small portraits, barely larger than a postcard, of heads and shoulders against a plain blue or green ground. The Dauphin who became King Henry II made him his court painter and valet, and the French elite sat for these little panels for decades.

Here is the odd part. Corneille never signed or dated a single work, and the first painting firmly tied to his hand was only identified in 1962. So many other artists worked in the same neat style that telling his panels from theirs is close to impossible, and most of what carries his name today is attributed rather than proven.