New research at the Nationalmuseum has shown that a painting in the collections, earlier ascribed to an anonymous artist, can now be attributed to Carel Fabritius, one of Rembrandt’s pupils.

Theo’s mother is killed in the attack, and Theo himself stumbles from the scene clutching a small painting, The Goldfinch, painted by 17th-century Dutch artist Carel Fabritius. The painter ...