In an age of bolters—women who broke the rules and fled their marriages—Idina Sackville was the most celebrated of them all. Her relentless affairs, wild sex parties, and brazen flaunting of convention shocked high society and inspired countless writers and artists, from Nancy Mitford to Greta Garbo. But Idina’s compelling charm masked the pain of betrayal and heartbreak.

Now Frances Osborne explores the life of Idina, her enigmatic great-grandmother, using letters, diaries, and family legend, following her from Edwardian London to the hills of Kenya, where she reigned over the scandalous antics of the “Happy Valley Set.” Dazzlingly chic yet warmly intimate, The Bolter is a fascinating look at a woman whose energy still burns bright almost a century later.