In 1951, a leading British art expert visited a stately home in Northamptonshire and viewed its paintings by old masters alone because the owner was ill.
Six years later, the wife of Boughton House’s owner popped into an American museum, where she was struck by a vivid portrait of a German prince by Anthony van Dyck that looked just like theirs. She was to discover that it was the very same painting by the 17th-century Flemish court painter to King Charles I, stolen from them.
