At key moments in Brazilian literary history, writers and critics adopted a commitment to realism and “authenticity” in literary production in order to define a common national identity, first as a Portuguese colony and then as an independent country. While the literary politics of these eras advocated for an objective approach to writing that afforded prominence to the poli tical and ideological imperatives of empire and then nation building, these demands were genre-specific and placed primarily upon fiction and poetry. The cost of this commitment to realism was a rejection of literatures of “invention” and writing deemed to be too subjective. In contradiction to the Brazilian demand for literary realism, then, was a rejection of auto/ biographical narratives thought to embody subjectivity. Although there certainly has been a contemporary movement in Brazil to read auto/biographical narratives as having both aesthetic value and being an important component of national identity, there is still a lingering devaluation of such texts for not being “real” enough or “literary” enough. This chapter explores how critics might work to understand the role of auto/ biographical narratives in building national identity and to situate them within the context of Brazilian national literary history, since these texts constitute two antithetical elements in the equation of realistic literature: documentary and subjectivity. Ultimately, this chapter suggests that auto/ biographical narratives-in particular diaries-are an essential means of understanding Brazilian national identity, both as a colony of Portugal and as a postcolonial country.