Amitav Ghosh has written extensively on various topical issues including terrorism, religious fundamentalism, displacement, history, identity and many postcolonial realities of the Third World. But his fictional oeuvre The Circle of Reason (1986), The Shadow Lines (1988), In An Antique Land (1992), The Calcutta Chromosome (1996), The Glass Palace (2000), Sea of Poppies (2008), and The River of Smoke (2011) is permeated by an underlying consciousness of the marginalized and the narrativization of the marginal’s experience. The Hungry Tide and Sea of Poppies trace the life of two marginalized characters respectively Fokir (an uneducated fisherman and son of illegal migrant) and Deeti( a widow) who had to face lots of difficulties to make their ways in life against the will of dominant class and emerge as new identities. Both novels are important interventions in so far as they foreground histories of those who are denied access to the realm of mainstream historiography. Moreover, the protagonists in both the narratives belong not to the elite or the powerful but to the powerless or minority. Ghosh highlights marginal’s central role in shaping history and politics .These are actually a short history of nation seen through the eyes of marginals. Ghosh’s perspective is always the viewpoint of a subaltern that tries to understand, react and arrange the situation to his/her understanding. The present study tries to deliberate upon that unlike mainstream historiography, Ghosh’s novels here especially The Hungry Tide and Sea of Poppies represent marginalized as active agent in shaping their world and gives them voice. This paper attempts to focus on the process whereby subaltern histories in the texts subvert geopolitical boundaries. Key Words: postcolonial, irreversible symmetry, cartographical divisions, protected trilogy, resistance to imperialism etc