Definition
Nationalism is defined as a term that describes a doctrine that believes that a nation has the right to constitute an independent or autonomous political community based on ethnicity or culture or shared history.
Origins
The origin of Nationalism is actually from ethnic groups or nations as a social reality dating back to twenty thousand years.
Modern versions of Nationalism were seen from around the 1800s, where in European states; national identity and unity were imposed by those from above, such as the government. Nationalism was seen as an essential tool to modernize the economy and the society. However, nationalism often led to unintended conflicts between different groups or countries. For example, one of the main causes of World War 1 was Nationalism.

Types of Nationalism
Nationalism is also divided into differing types, Civic Nationalism, Ethnic Nationalism, Expansionist Nationalism, Romantic Nationalism, Cultural Nationalism, Liberal Nationalism, Anarchism and Nationalism, and Religious Nationalism.
Civic Nationalism
Civic nationalism is the form of nationalism whereby the state derives political legitimacy from the active participation of its citizens, from the degree to which it represents the people’s wishes and sentiments
Ethnic Nationalism
Ethnic nationalism defines the nation in terms of ethnicity, which always includes some element of descent from previous generations. It also includes ideas of a culture shared between members of the group and with their ancestors, and usually a shared language.
Expansionist Nationalism
Expansionist Nationalism is a radical form of nationalism that incorporates autonomous, patriotic sentiments with a belief in expansionism, which is the act of gaining more territory or assets. It is most closely associated with Nazism.
Romantic Nationalism
Romantic nationalism is the form of ethnic nationalism in which the state derives political legitimacy as a natural consequence and expression of the nation, or race.
Cultural Nationalism
Cultural nationalism defines the nation by a shared culture. Membership in the nation is neither entirely voluntary (one cannot instantly acquire a culture), nor hereditary (children of members may not be considered as members if they were exposed and believe in other cultures).
Liberal Nationalism
Liberal nationalism is a kind of nationalism that believe that there can be a non-xenophobic form of nationalism compatible with liberal values of freedom, tolerance, equality, and individual rights.
Anarchism and Nationalism
Anarchists who see value in nationalism normally argue that a nation is first and foremost a people; that the state is parasite upon the nation and should not be confused with it.
Religious Nationalism
Religious nationalism defines the nation in terms of a common religion, usually along with other factors such as culture, ethnicity, and language.
References
Handler, R. (n.d.). The Nationalism Project: Richard Handler on "Nationalism". Retrieved March 23, 2008, from http://www.nationalismproject.org/what/handler.htm.
Mauro, R. M. (n.d.). The ideology of nationalism or nationalistic ideology?Nationalism as strategic political thinking, not ideology political thinking. Retrieved March 23, 2008 from Political Study Association, Department of political science Web site: http://www.psa.ac.uk/2007/pps/Mauro.pdf
Nationalism (The Best Political Ideology). (n.d.). Retrieved March 23, 2008, from http://bestuff.com/stuff/nationalism.
Nationalism - Wikipedia, the free encyclopedia. (2008, March 17). Retrieved March 22, 2008, from http://en.wikipedia.org/wiki/Nationalism.