For centuries the story went that Jan van Eyck invented oil painting overnight. This episode dismantles that Vasari myth and replaces it with something more impressive: a scholar-painter who knew Latin and worked Greek and Hebrew letters into his panels, who served as valet de chambre to John of Bavaria and then Philip the Good of Burgundy, and who was sent on secret diplomatic missions to distant lands. Historians believe the accurate Jerusalem skyline in The Three Marys at the Tomb came from one such trip.

We follow the 1428 mission to Portugal, where plague trapped him for nine months at the Castle of Avis while he painted Princess Isabella’s portrait for a duke he could not disappoint. The reward was a fixed salary allowing him to paint whenever he pleased, and that gift of time is what made his revolution possible: thinning oil into translucent glazes over a white chalk ground so that light passes through and reflects back, creating paintings that seem to glow from within.

• Why egg tempera dried too fast to blend and how thin oil glazes solved the problem
• The stubble on his sitters and the subtle flattering of his wife Margaret’s nose and forehead
• His motto Als Ich Kan and the Arnolfini inscription that declared Jan van Eyck was here
• How Erwin Panofsky explained the giant Virgin and impossible architecture of Madonna in the Church
• The Ghent Altarpiece, his death in Bruges in 1441, and the widow who invested his payout in the city lottery