The diplomatic essays of Harold Nicolson (1886-1968) have been considered classics in the field of International Relations, while his biographical essays and fictions have largely been neglected by English literary critics. In a similar vein, poetry and fiction have dominated as subjects for analysis among the critics of modernism while autobiography and biography have been much less studied. Although the present literary studies largely disregard modernist biography and Nicolson, they were widely discussed and read among their contemporary biographers. For instance Virginia Woolf introduced Some People (1927) as a modern biography for the modern world, and appraised the new method that Nicolson created. This article attempts to reexamine modernism in terms of auto/biography, focusing on the new phase of biography Nicolson introduced. His auto/biography, which articulates war experiences as a postwar writing, is here analysed in diplomatic as well as biographical terms. In conclusion, I propose that he reproduce the new imperial citizenship through his new writing. Furthermore this essay also investigates the polit\ical unconscious of this period by the examination of biographical essays of Woolf and Sydney Lee as well as of Nicolson.