To research "Centuries of Success: Lessons From the World's Most Enduring Family Businesses," William T. O'Hara traveled thousands of miles to exotic locations and spent hundreds of hours interviewing executives of 20 incredibly long-lasting family enterprises. The result is a combination travelogue and history of business that reads well, and teaches effectively.

The companies selected by O'Hara, a former president of Bryant College in Rhode Island and founder of the Institute for Family Enterprise there, form the ancient to the merely old. In the first category is Kongo Gumi, a Japanese temple restoration firm that has been continuously family operated for an astounding 14 centuries. Founded in 578, Kongo is still run by descendents of the Korean immigrants who began it. Among the lessons passed on to the 40th generation to run this company are, "Don't diversify. Concentrate on your core business." Surely that must be an entry in "The more things change, the more things stay the same."

The youngest firm is the comparatively immature and prosaic Maryland bakery supply firm George R. Ruhl & Sons, founded in 1789. Most of the companies studied by O'Hara are located outside the United States, and many are in exotic fields, such as Italian arms manufacturer Beretta, which claims to be the world's oldest industrial concern at age 479. Beretta, with annual sales of around $260 million is one of the biggest companies profiled, while fellow Italian enterprise Confetti Mario Pelino notched sales of just $4 million in 2001, despite being in operation under the stewardship of the Pelino family since 1783.

O'Hara takes pains to draw what business lessons he can discern from each family's corporate history, and many are illuminating. For instance, he applauds the way the father of Piero Antinori completely and irrevocably turned over the reins of 600-year-old wine maker Chianti to his 28-year-old son in 1966. "Too many aging CEOs allow themselves to recline behind their desks and wait until the decline becomes precipitous before passing the torch," O'Hara notes. The young son was able to overcome marketing challenges that had defied his 68-year-old father, significantly reviving and expanding the Chianti brand. The lesson: Let a new generation tackle new problems.

Of particular interest is the concluding chapter, where O'Hara summarizes 11 traits he saw repeating among the 20 case studies. Perhaps most interesting of all is his admission that many of the firms did not share all 11 traits. For instance, only three practiced the policy of adopting a successor into the family to maintain continuous ownership. Nevertheless, he identifies adoption as a valuable tool for building a long-lasting family firm. Also, other traits, including using a written strategic plan and emphasizing community and customer service, are less than universal in this sample.

Two traits, he says, are found in all the long-surviving firms. They are family unity and a commitment to continue the legacy. Obvious? Perhaps. But how many family firms fail to explicitly state that the enterprise is intended to remain in family hands for the long haul? If your firm is one of those that hasnšt stated that clearly, but you'd like to be remembered as long and as well as one of the businesses in O'Hara's book, that's a lack you might want to address.