Most people recognize the name of famous billionaires like Warren Buffett or Bill Gates, but the name Shelby Cullom Davis doesn't ring as many bells. Davis began his investing career in 1947 with $50,000. When he died in 1994, he was worth around $1 billion.

"The Davis Dynasty," written by John Rothchild, tells the story of the three generations of the Davis family who have arguably been some of the most successful investors in the history of Wall Street. "The Davis Dynasty" isn't just a book -- it's a lesson on good, albeit somewhat unexpected, investing decisions. In the following video, Motley Fool financial analysts Matt Koppenheffer and David Hanson discuss the valuable lessons to be learned from the Davis family's unique investing history. Koppenheffer discusses how Davis's concentrated portfolio of insurance stocks allowed him to gain a competitive advantage over other investors in that space. The guys also debate the difficulties in having the conviction to not sell your shares of a company when the stock's valuation creeps into "overvalued" territory.