The Wildenstein family has one of the world’s biggest art collections, “worth an estimated €10 billion, and connections that have allowed them to broker some of the Louvre’s biggest purchases.” Now “Alec and Guy Wildenstein, whose father Daniel died four years ago, will challenge a French court ruling in favour of their 71-year-old stepmother Sylvia to break up the huge private collection, believed to include Renoirs, Monets and Manets.”