Answer:
The rise of Nationalism in Europe in this period is connected with the ideas of Romanticism and necessity for the creation of national states. It all started after the wave of revolution from United States was spreading across Europe. It started in France and the creation of Republic and ended with unification of Germany and Italy.
Step-by-step explanation:
National ideas were usually threatened by absolute monarchies, that existed in Austria, France and other countries. But when the wave of revolution started everything changed. The emergence of national unification was spreading in Italy, Balkan states, even on the soil of Austrian Empire. It led to numerous revolution, among which the one from 1848 was the most important one.