The story of El Dorado is explored further in the Lost Kingdoms of South America, a series for BBC Four starting on Monday 14January at 21:00 GMT and the British Museum Digital Exhibition.

BBC: El Dorado: The truth behind the myth

As they have built their business kingdoms, they have lost their spouses through divorce and their children hardly know their names.

FORBES: Starting a Business Requires Sacrifice

And because of this complexity, the senior managers back at headquarters lost track of what was being done in the various corners of their kingdoms, and the risks associated with those actions.

FORBES: Too Big to Fail -- Or Too Complex to Succeed?