In the famous photograph of the 1921 Cairo Conference, amid Winston Churchill, T.E. Lawrence, and a sea of British diplomats redrawing the map of the Middle East, stands a single woman in a feathered hat, entirely at ease. Gertrude Bell earned that seat by breaking nearly every rule available to a Victorian aristocrat: first woman to take first-class honors in modern history at Oxford (which refused to hand her the actual degree), an extreme mountaineer who survived 53 hours roped to an Alpine cliff in a storm, and a desert traveler so fluent in Arabic and tribal politics that Bedouin called her "daughter of the desert."

Grief drove much of it: a fiancé blocked by her father and then suddenly dead, a married love lost at Gallipoli. She channeled it into an 1,800-mile trek to Ha'il, where she talked her way out of 11 days of captivity, and i ...