This thesis considers the dialectic of innocence and experience in the fiction of A.L. Barker (1918-2002). It is about her preoccupation with the relation between these states, which I argue is best understood through the figure of the child. Alluding to and critiquing Romantic, Victorian, psychoanalytic and modernist narratives of childhood and registering their influence on ideas about the child in mid-twentieth-century culture, Barker’s fiction troubles dominant assumptions about what different identities of age entail, meaning that her oeuvre should be read as a ‘genealogy’ of age. I argue that the central question of Barker’s work is if, and how, the child can be written. She wrestles with this question for over thirty years, writing and rewriting the child figure in a number of alternative, innovative forms: the short story, the ‘articulated novel’ and the retropulsive text. In each case she is preoccupied with the ways in which the child mirrors or intertwines with other categories of age that are constructed in opposition to adult identity. The thesis recognises the significance of the child figure in mid-twentieth-century literature and highlights age as a crucial (though under-used) critical concept for reading modernist and after-modernist texts. In this way it contributes to recent literary debates concerning childhood and modernism and also takes part in discussions of age in Childhood Studies and in the newly-emerging field of Age Studies, which recognises age to be an attribute of identity as significant as gender, race, class, sexuality, disability, and so on. The thesis makes a distinct contribution to literary studies by providing the first introduction to Barker’s work and writing life, based not only on in-depth analyses of her published texts but also on extensive archival research undertaken at the A.L. Barker archive at the Harry Ransom Humanities Research Center.