Mario Gabello built his empire in 1976, when he was only 34-years-old, on a $50,000 check. He went to Branford, Conn to meet with Frederick J. Mancheski, then chairman and CEO of Echlin, Inc. and Mancheski became his first backer, The New York Times reports.

"He came in one day and said he was thinking of starting his own firm to manage money," Mancheski, now 79, said. "I told him I thought he had the know-how, and he asked me if I'd be interested in investing in it."

Gabelli, now 63, has gone on to become one of the most successful mutual fund managers around, with $28 billion of assets under management. He has huge stakes in some of the world's largest media companies and Barron's has listed him among the world's greatest stock pickers. On Wall Street, and at his firm, Gamco Investors, Gabelli has come to be known as Super Mario.

But Super Mario's empire may be crumbling. Despite making his name as being a voice of shareholder rights, he is under attack and is accused of corporate abuses by none other than Mancheski, his original backer and the second-largest investor.  Mancheski has filed suit against Gamco, contending that Gabelli and his firm's directors "are guilty of looting the assets of the company, breaching their fiduciary duties to its shareholders and oppressing its minority shareholders."

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