Nationalism is an idea and movement that holds that the Nation should be congruent with the state. As a movement, it presupposes the existence and tends to promote the interests of a particular nation, especially with the aim of gaining and maintaining its sovereignty (self-governance) over its perceived homeland to create a nation-state. It holds that each nation should govern itself, free from outside interference (self-determination), that a nation is a natural and ideal basis for a polity, and that the nation is the only rightful source of political power. It further aims to build and maintain a single national identity, based on a combination of shared social characteristics such as culture, ethnicity, geographic location, language, politics, religion, traditions and belief in a shared singular history, and to promote national unity or solidarity. Nationalism, therefore, seeks to preserve and foster a nation's traditional culture. There are various definitions of a "nation", which leads to different types of nationalism. The two main divergent forms identified by scholars are ethnic nationalism and civic nationalism.
Title page from the second edition (Amsterdam 1631) of De jure belli ac pacis
A postcard from 1916 showing national personifications of some of the Allies of World War I, each holding a national flag
Senator Johan Vilhelm Snellman (1806–1881), who also possessed the professions of philosopher, journalist and author, was one of the most influential Fennomans and Finnish nationalists in the 19th century.
A painting by Alphonse-Marie-Adolphe de Neuville from 1887 depicting French students being taught about the lost provinces of Alsace-Lorraine, taken by Germany in 1871
A state is a political entity that regulates society and the population within a territory. Government is considered to form the fundamental apparatus of contemporary states.
Painting of Roman Senators encircling Julius Caesar
The frontispiece of Thomas Hobbes' Leviathan