In May 2019 workmen started to dig up Kalandeberg square, not far from St Bavo’s Cathedral in the Belgian city of Ghent. There was, however, no trouble with a water main or gas pipe; what the excavators were after was a missing piece of one of the world’s greatest artworks, the Ghent Altarpiece.
The altarpiece, 11ft high by 15ft wide and comprising 24 paintings, was commissioned from Hubert van Eyck in the 1420s but was largely unfinished at his death in 1426. The work was taken up by his younger brother Jan, who was, according to a now lost inscription on the frame, “second best in the art” (Hubert was “greater than anyone”).