Individuals are always identified with their origin, be it the cast, community, religion and for that matter, the country to which they belong to.  Of all the above identities, it is the nation which plays an important role in shaping of life of an individual.  It is an inseparable aspect of a human being. And every country has its own past as a laying stone on the basis of which future  of the nation is built up. It is this nationalist approach towards identification that we are referring to here. Hence Nationalism is an   ideology that involves a strong identification of a group of individuals with a nation. 

The concept of nationalism can be seen from the two different angles i.e.  (i) historical perspective and (ii) modern day perspective.  The historical  aspect of  the nationalism is described in terms of reflection of the ancient glory and perceived evolutionary tendency of humans to organize into distinct grouping based on an affinity to a particular place of  birth; in a definite geographical area. 
... to be continued