Icahn, whose net worth is now $17.9bn according to Forbes, became Caesars’ largest individual shareholder earlier this year with the aim of pushing through a merger.

Hiring Tony Rodio as CEO – just as he had done with Tropicana Entertainment before it was also purchased by Eldorado – the billionaire ultimately achieved his goal, for which he has praised the Caesars board.

A statement on Icahn’s website read: "This merger is the quintessential example of how an activist shareholder, working collaboratively with the board, can greatly enhance value for all stockholders.

"While I criticised the board when I took a major position several months ago, I would now like to do something I rarely do, which is praise a board of directors for acting responsibly and decisively in negotiating and approving this transformational transaction."

An impassioned Icahn continued to take aim at the philosophy of boards and executives across the US, comparing corporations to "feudal systems" in a fascinating sequence.

The Caesars investor said: "Unfortunately, there are far too many boards that, unlike Caesars, believe corporations are more like feudal systems than democracies; that stockholders are the peasants who represent a necessary evil which must be tolerated, possibly patronised, but certainly ignored.

"Much like the feudal barons, they hire mercenaries (lawyers and investment bankers) to deal with these peasants (stockholders), if they become too unruly."