The painting had been assumed to be a later copy because it's different to the original in detail, and the thick yellow varnish had concealed the quality of the vivid reds, blues and golds. But Rachel Turnbull, a senior conservator at the charity English Heritage, which cares for hundreds of historic sites, said that X-ray and infrared tests showed an under-drawing and changes to the composition that's uncommon in imitations.
"It was of the right period, it was technically correct and it was painted on poplar, a material commonly used at the time," she said. The circular painting, part of a collection bought by a diamond magnate, shows angels flanking Mary, who holds baby Christ and a pomegranate symbolizing his future suffering. Though small, it includes exquisite details and features gold leaf adorning Mary's halo and the wings of the angels worshipping her.
It will go on display in Ranger's House, a Georgian villa in southeastern London, from April 1.