JOHN EGERTON CHRISTMAS PIPER was one of the 20th century’s great polymaths. A watercolourist in the romantic tradition of Turner, Girtin and Cotman, he was also a pioneer of abstract art in Britain, designer of stained glass, textiles, tapestries, ceramics, stage sets and costumes; a printmaker, muralist, writer, photographer and ‘firework master’, as a current exhibition at the Portland Gallery, London SW1, highlights. He was also a medievalist, who, in an article for Architectural Review (October 1936) declared that the ‘purely non-figurative artists of some of the early Northumbrian and Cornish crosses were the forebears of the pure abstractionists of today’. If there is one pre-eminent strand that runs consistently through Piper’s work, it is his enduring love of Northern European sculpture, from the Dark Ages through to the 15th…