Devoted, eccentric, and compelling, Gertrude and Leo Stein were constant companions, from childhood to adulthood, until, finally, they spoke no more. Americans, expatriates, and virtually orphans, they lived together for almost forty years, collaborating in one of the great artistic and literary adventures of the twentieth century. Sister Brother tells the story of that adventure and relationship. With a personality that drew people toward her—regardless of what they thought of her inventive, hermetic prose—Gertrude Stein dazzled and perplexed. Enigmatic, intelligent, and self-absorbed, Leo also dazzled but in his own way. One of the crucial figures in Gertrude’s early years, he was the original guiding spirit of the famed salon at 27 rue de Fleurus, which continued for almost two decades. From her early days as a medical student to her first days in Paris, Gertrude was passionately driven toward the career in which she distinguished herself, demanding appreciation as an exceptional writer who knew precisely what she intended. This book shows how Gertrude slowly struggled with what became a unique voice—and why her brother spurned it. With its wealth of new and rare material, its reconstruction of Leo’s famed art collection, and its array of characters—from Bernard Berenson to Pablo Picasso—this biography offers the first glimpse into the smoldering sibling relationship that helped form two of the twentieth century’s most unusual figures.