Like many politicians of a revolutionary turn of mind, Barbara Castle was of the middle class.

ECONOMIST: Barbara Castle

Investment, consulting and project management company Vicon wants to redevelop the castle itself as the "centrepiece" of a development that proposes "a world-class championship-standard 18-hole golf course, clubhouse and educational golf academy, new whisky distillery, homes, retail and a food and drink centre of excellence".

BBC: Loudoun Castle

First Castle looks for industries making unsexy, overlooked products like diamond-studded drill-bit inserts, airplane toilets and class rings.

FORBES: The LBO Method