'It is the battle between those who use a toothbrush and those who don't.' So wrote Augusta Gregory to W.B. Yeats; she was referring to the riots at the Abbey Theatre over The Playboy of the Western World, and she knew which side she was on. In this remarkable biographical essay, Colm Toibin examines the contradictions that defined the position of this essential figure in Irish cultural history, The wife of a landlord and MP who had been personally responsible for introducing measures that compounded the misery of the Irish peasantry during the Great Famine, Lady Gregory devoted much of her creative energy to idealizing the same peasantry -- while never abandoning the aristocratic hauteur, the social connections or the great house which her birth and marriage had bequeathed her. Early in her writing life, her politics were staunchly unionist -- yet she campaigned for the freedom of Egypt from colonial rule. Later she wrote plays celebrating rebellion, but trembled in her bed when the Irish revolution threatened her property and her way of life. Lady Gregory's capacity to occupy mutually contradictory positions was essential to her heroic work as a founder and director of the Abbey Theatre -- nurturing Synge and O'Casey, battling rioters and censors -- and to her central role in the career of W. B. Yeats. She was Yeats's artistic collaborator (writing most of Cathleen Ni Houlihan, for example), his helpmeet, and his diplomatic wing. Toibin's account of Yeats's attemts -- by turns glorious and graceless -- to memorize Lady Gregory's son Robert when he was killed in the First World War, and of Lady Gregory's pain at her loss and at the poet's appropriation of it, is a moving tour de force of literary history. Toibin also reveals a side of Lady Gregory that is at odds with the received image of a chilly dowager. Early in her marriage to Sir William Gregory, she had an affain with the poet and anti-imperialist Wilfred Scawen Blunt and wrote a series of torrid love sonnets that Blunt published under his own name. Much later in life, as she neared her sixtieth birthday, she fell in love with the great patron of arts John Quinn, who was eighteen years her junior. Lady Gregory's Toothbrush is a sharp, concentrated, witty and much-needed reassessment of a major cultural figure who has been oddly taken for granted and often badly misunderstood.