Two hundred–odd years ago, an energetic fellow from Corsica ruled over much of continental Europe, with designs on the Americas once he settled matters closer to home. A couple of strokes of bad fortune late in his game, suffered in Russia and Belgium, undid old Napoleon Bonaparte, but while he was at the top of it, he had plenty of people worried about what his next move would be.

Even while ruling over millions of square miles of territory, Napoleon found time to insinuate himself into the affairs of his family. So it was with his brother Jérôme, a naval officer who met Baltimore belle Elizabeth Patterson at a ball and fell in love. “Like the fairy-tale hero who rescues the imprisoned maiden from the tower, Jérôme could rescue Betsy from that life of tedious domesticity she feared was her future if she remained in America,” writes Carol Berkin, Presidential Professor of History at Baruch College, in her new book Wondrous Beauty: The Life and Adventures of Elizabeth Patterson Bonaparte. She adds that Jérôme himself had no such vaulting ambitions but simply liked what he saw, marrying the 18-year-old as soon as he could arrange it.

It didn’t hurt that Betsy’s father was among the richest men in America. But Napoleon had other ideas. He wasn’t above dumping his beloved Josephine in order to marry up the chain of nobility, after all, and just so, forbidding Betsy to set foot anywhere on French-occupied Europe, he had the marriage annulled and ordered Jérôme to marry a German princess.

Though unhappy about it, Jérôme complied. Heartbroken, his bride returned to Baltimore. She never married again, though she was not without admirers, for she cut a formidable figure for much of the rest of her long life—literally, for Betsy was fond of fashions that revealed a bit more of herself than was the norm, and she retained her beauty for decades.

After formally divorcing Jérôme, she turned the settlement Napoleon had given her and an inheritance from her father into a great fortune, which allowed her to raise her son with Jérôme in comfort. That son, Jerome Napoleon Bonaparte, in turn had a son, Charles Bonaparte, who grew up to be a brilliant lawyer who served in the administration of Theodore Roosevelt, first as secretary of the navy and then as attorney general. One observer neatly branded him “by instinct a royalist, by profession a democrat and reformer.” Just as his father had declined a royal title, Charles never traveled to France or otherwise traded on the family name, devoting himself to good works back home. By all accounts, he was a fine fellow.

Yet, for all his brilliance, Charles is almost forgotten today, his bloodline having died with him in 1921. Were it not for Berkin’s book, his grandmother Betsy would likely enjoy the same fate, at least outside the city limits of Baltimore, where she remains something of a local legend.

Berkin came upon Betsy’s story courtesy of documentary filmmaker Ron Blumer, with whom she had collaborated. “Sitting over dinner one night a few years ago,” she recalls, “I confessed that I didn’t really know what my next book was going to be about. This happens to every historian after finishing a project, thinking, ‘Oh, my God, I’ll never think of another subject.’ Ron said, ‘I know exactly what book you should write. In fact, I demand that you write about Betsy Patterson.’ He had found out about her while working on a film about her friend Dolley Madison, and he told me a bit about her. I was intrigued, and when I did a little digging, I found her fascinating.”

Berkin found a trove of materials to work with in the form of Betsy’s letters and other documents held by the Maryland Historical Society. But beyond that, she had to do more than a little digging. “When you write a biography,” she says, “you have to create a context by examining the lives of all the people the subject knew. You wind up weaving a kind of elaborate spider web of connections. That took some detective work, but it’s quite remarkable how many of them kept diaries—and how many of those diaries you can read online for free, which makes the work so much easier than it was when I was starting out.”

Betsy Bonaparte lived to the age of 94, and even in her later years she was still an object of fascination, with newspaper reporters calling on her for a taste of her sometimes-caustic commentary on the events of the day. Those last years, Berkin says, were lonely ones, for Betsy outlived all her friends—and her enemies as well, to say nothing of her former husband and in-laws.

But that celebrity, Berkin writes, is just part of Betsy Bonaparte’s story. She was stunningly beautiful, true, and briefly connected to one of history’s most famous families. But her influence was more profound. For one thing, she was a shrewd critic of her own society, decrying the penchant of American men for mere moneymaking and their need to confine women “to the parlor and the nursery.” Yet she herself was a distinctly capable businessperson, parlaying the fortune she inherited into a still greater one—and, as Berkin writes, nursing “an obsession with wealth and its acquisition that would have won the admiration of any American man.”

Perhaps she did so because she harbored a drive to become rich. More likely, she sought wealth in order to be and to remain independent, never having to rely again, after bitter experience, on any man for any corner of her future.

In that alone she is a strikingly modern figure. But Elizabeth Patterson Bonaparte is fascinating on many other levels as well, and Berkin brings her to life in this brief but comprehensive biography. For her part, Betsy provides one more lesson for students of history as well. “To our peril,” Berkin says, “we continue to believe that it is the great men of the past alone who made history. There’s more to the story than that, as Betsy shows us.

“In the end, I found myself caring a great deal about her,” she adds. Readers will, too.

Gregory McNamee is the contributing editor of Kirkus Reviews.