With the dawn of twenty first century the phenomenon of globalisation began to be widely recognised as a force continuously drawing people of the world towards each other. It’s manifestation can be seen in the form of increasing global exchange between different nations in the fields of trade and commerce, information and technology, education, culture, food, life style etc. Thus turning the world into a global village which undermines the significance of unitary national identity and nationalism; nationalism from the preceding century continues to be a portent force and has resulted in the formation of many independent nations from the yoke of European colonial empire through various nationalist struggles. Now in the post-colonial era newly independent countries are in a quest of self identity as they are attempting to assert their individuality as nations and shed the yoke of being culturally, politically, and economically oppressed for a long time in their history by European colonial powers. Therefore, the official ideologies of the current nation-states tend to propagate notions of purity, unity, and shared heritage among its people so as to gain their confidence for being a politically, socially, and economically sovereign state. However, national ideologues have failed in their attempt to assert their version of nationality and nationalism as people have moved in time and space and have become culturally, economically, and religiously comingled in ways that modern demarcations of nationality fail to consider and have become artificial in the sense that it is man-made and inadequate to meet the demands of people of the modern times.Nations are a piece of land demarcated by barbed wires and trenches within which live people of different ethnic origins, religious beliefs and, cultural traditions. Benedict Andersonregards nation as an “imagined community” because he believes it to be a mental construct that houses people within its boundaries who otherwise have never known or met each other but still think to be related to each other on the ground that they belong to the same nation. It is not imaginary in the sense that nations are unreal rather are a kind of psychological conditioning which binds people elementally who otherwise may be spatially and socially separate. Anushuman Mondal notes that “nations are real and imaginary, material and immaterial” (88).In this chapter I shall workout the ways in which Amitav Ghosh understands nation as a concept and the ways he deals with the issues of cross-cultural and cross-border permeations that exist between people of different cultures and nations in both pre-colonial as well as post-colonial times; in The Shadow Lines Ghosh has emphasised upon the cordial relations existing between various religious groups in times of need, between Indians and their British counterparts before and after the independence of the country. This chapter will also deal with the concepts of national borders, both physical and imaginary ones, the historical processes by which they have come into being, their place in the narration and memory of people associated with them, and the resulting ironies that affect people’s lives at times in incomprehensible ways in the post-colonial era rich with contradictions. The chapter will also focus on the historical narrative of creation of nations and myths concerning nation building in the imagination of people by the dominant nationalist discourses.There are many theorists who have deliberated on the concept and origins of nation, some argue that the existence of globalisation have undermined the significance of nationalism because one’s national identity has lost its value in the increasingly multicultural societies. Others however argue that in the present era, nationalism is being influenced in its form only and they put forth the example of growing group identification tendencies among ethnic groups, religious groups, ethno-language groups etc. For Earnest Renan “A nation is a soul, a spiritual principle. Two things, which in truth are but one, constitute this soul or spiritual principle. One lies in the past, one in the present. One is the possession in common of a rich legacy of memories; the other is the present-day consent, the desire to live together, the will to perpetuate the value of the heritage that one has received in an individual form” (Renan 19). Gellner points out that nationalism is a sentiment or the feeling of anger aroused by the violation of principle, or the feeling of satisfaction aroused by it. It can also be a movement actuated by it. Furthermore, he argues that the innovation of written word and the emergence of literacy as factors helping the development of nationalism in the agrarian society in European history. And, in African, Asian, and Latin American countries the development of nationalism has resulted due to a struggle against the western imperialism.To John Plamenatz, “nationalism is a desire to preserve or enhance a people’s national and cultural identity when that identity is threatened, or the desire to transform or even create it where it is felt to be inadequate or lacking” ( 23-24). Elaborating further, he argues that nationalism movements are basically cultural in nature but may sometimes take political form as well. Plamenatz elaborates that “nationalism tend to arise when people are aware of cultural diversity and change, and share same idea of progress which move them to compare their own achievements and capacities with those of others” (Plamenatz 27). In contrast to Plamenatz Hugh Seton-Watson is of the view that nationalism is a pejorative term used in opposition to the word patriotism. For him nationalism, firstly, can be a doctrine about character, rights and duties of nations, secondly, it may be an organised political movement, designed to further the alleged aims.