It is true that "the first clear expression of nationalism came with the 'French revolution' in 1789′′.
(i) Till 1789, France was a full-fledged territorial state under the rule of absolute monarch. The political and constitutional changes that came during the rise of the French Revolution, led to the transfer of sovereignty from monarchy to the body of French citizen.
(ii) The revolution proclaimed that it was the people who would hence forth constitute the nation and shape its destiny.
From the beginning, the French revolutionaries introduced various measures and practices that could create a sense of collective identity, and a feeling of nationalism among the French people. The community was enjoying equal rights under the constitution.
(iii) A new French flag, the tri-colour, was chosen to replace the former royal standard. The Estates General was deleted by the body of active citizens and renamed as National Assembly. New hymns were composed, oaths were taken and martyrs were commemorated, all in the name of nation.
(iv) Regional dialects were discouraged and French, as it was spoken and written in Paris, became the common language of the nation.
The revolutionaries further declared that they would help other people of Europe to become free nations. When the news of the events of France reached different cities of Europe, students and other members of educated middle classes began setting up Jacobin Clubs. Their activities and campaigns prepared the way for the French armies which moved into Holland, Belgium, Switzerland and much of Italy in 1790 s.
Thus, with the outbreak of revolutionary wars, nationalism spread in the entire Europe.