HER BRILLIANT CAREER: PAMELA HARRIMAN (1920-1997)

She lived one of the most remarkable lives of the 20th century, too implausible for a romance novel or a Hollywood blockbuster. A vivacious English aristocrat, she married Winston Churchill's only son at the outset of World War II, then a legendary Broadway producer and finally one of America's best-known and richest statesmen, before earning her own political stripes, transforming herself into a woman of substance and flourishing anew as the highly respected U.S. ambassador to France.

Along the way she charmed Presidents and policymakers, diplomats and decorators, even as she terrified wives by having affairs with their husbands, some of...