Genter Altar

Finished in 1432 and signed by Jan van Eyck, who credited his brother Hubert with beginning it, this huge folding altarpiece was one of the first great works in oil paint, and the new medium let van Eyck build up glazes so fine you can read the individual jewels and hairs. Opened out it is a wall of panels, with a lamb on an altar at the centre and crowds of saints and pilgrims streaming toward it across a spring meadow. For 6 centuries it has been one of the most fought-over objects in Europe. Napoleon's men took panels to Paris. The Nazis hauled the whole thing into an Austrian salt mine, and the Monuments Men pulled it back out at the end of the war. But one loss was never undone. On the night of the 10th of April 1934 thieves prised out the lower left panel, the Just Judges, from Saint Bavo's Cathedral in Ghent. A man confessed on his deathbed that year but never said where it was, and it has never been found. The panel you see in that spot today is a copy, painted in the 1940s to fill the gap, and Ghent police still keep a file open on the case.