Il vino di San Martino

For most of its life this was a lost painting hiding in plain sight. It hung in a Spanish collection under Bruegel's name, but few believed it, until the Prado studied it around 2010, stripped back a thick layer of varnish, and found fragments of his signature under X-ray. It turned out to be the largest thing Bruegel ever painted, and one of the few surviving works in a fragile old technique, glue-based tempera brushed straight onto unprimed linen. The subject is Saint Martin's Day, when the first wine of the year was tapped. Bruegel packs a whole crowd around the barrel, old men and children, beggars and thieves, all shoving for a share, while at the edge Saint Martin on his horse cuts his cloak in half for a poor man. The linen has worn thin in places, part of why it went unrecognised for so long.