THE VILLA, by Nora Roberts

A classic glamorous family saga by the New York Times best-selling mistress of the genre.
In this case, we have two families, the first, the Giambellis, have been winemakers for generations, is based both in northern Italy and Napa Valley, California. Led by the unnaturally proud, inflexible and autocratic La Signora, matriarch and undisputed ruler of both family and business, Giambelli has allied themselves with the all-male  MacMillan family of winemakers. La Signora is married to Eli MacMillan, whose son Tyler is the winemaker and ruler of the vineyards. La Signora's grand-daughter, Sophia, is Giambelli's head of publicity, a hard-charging powerhouse of a woman who takes no prisoners either professionally or personally. Click for more, but no spoilers...
Sophia and Tyler are lifelong friends. But nothing else. Sophia's father, long separated from Sophia's mother, is Anthony Avano, high-living head of sales for Giambelli. Anthony lives a bit too high, and his coldly calculating mistress/girlfriend/fiancee sees to it that he treats her in the way she wishes to become accustomed. And then, in one unanticipated stroke, La Signore throws many too-comfortable lives into chaos as she announces a reorganization of the entire upper echelon of Giambelli.
Okay, that's the back story and the first third of the novel. Read the rest. If you're into this kind of richly-detailed, sprawling fiction, this is the perfect weekend read. A 5.