By the time Isabella Stewart Gardner opened her Italian palazzo-style home as a museum in 1903 to showcase her collection of old masters, antiques, and objects d'art, she was already well-known for scandalizing Boston's polite society. But when Isabella first arrived in Boston in 1861, she was twenty years old, newly married to a wealthy trader, and unsure of herself. Puzzled by the frosty reception she received from stuffy blue bloods, she strove to fit in. After two devastating tragedies and rejection from upper-society, Isabella discovered her spirit and cast off expectations.

Freed by travel, Isabella explores the world of art, ideas, and letters, meeting such kindred spirits as Henry James and Oscar Wilde. From London and Paris, to Egypt and Asia, she develops a keen eye for paintings and objects, and meets feminists ready to transform nineteenth century thinking in the twentieth century. Isabella becomes an eccentric trailblazer, painted by John Singer Sargent in a portrait of daring décolletage, and fond of such stunts as walking a pair of lions in the Boston Public Garden.

The Lioness of Boston is a portrait of what society expected a woman's life to be, shattered by a courageous soul who rebelled and was determined to live on her own terms.