What Accounts for the Rise of European Nationalism During the 1800s?

European nationalism rose during the 1800s as a result of great political turmoil and upheaval. Sparked in part by the outcome of the American and French revolutions, populations throughout Europe began to unite in order to overthrow existing power structures and develop new ones based on liberty and national identity. While this did much to change things for the better, the rise of nationalism in Europe also contributed to a marked increase in xenophobia and the deaths of millions as a result of wars fought throughout the Continent.
1 Romanticism and National Identity

Romantic movements in art and culture beginning in the early 19th century led to the development of various national identities in Europe. The British poet Lord Byron did much to increase the European public's perception of nationalist uprisings. His poetry and involvement in the Greek War of Independence during the early 1820s sparked a significant amount of interest in the cause of Greek nationalist revolutionaries. As a result, public sentiment compelled several Western nations to support the uprising. This intervention helped Greece to achieve its independence from the Ottoman Empire and become the first "new" nation in Europe.
2 The November Uprising in Poland

For several decades prior to the success of the Greek nationalists over the Ottoman Empire, the political landscape of Poland had been divided and partitioned among several major European powers. In 1829, Nicholas the I of Russia was crowned King of Poland, which was a devastating blow to any prospects of Polish independence. Galvanized by the success of the Greek War of Independence, on November 29, 1830, the Polish representative government, known as the Sejm, declared its independence from Russia. This led to a disastrous revolt against the Russian military, which ultimately led to the surrender of Poland and the killing or wounding of over 40,000 Polish troops. This event was immortalized by the famed Polish pianist and composer Frédéric Chopin in a piece for piano called the Revolutionary Étude.
3 "Realpolitik" and the Unification of Italy and Germany

During the mid to late 19th century, nationalist "realpolitik" spurred the unification of two major European nations: Italy and Germany. "Realpolitik" is a practical approach to political diplomacy based largely on power dynamics between nations and other material factors. Camillo Benso, Count of Cavour from the Italian nation-state of Sardinia, is best known for his successful application of "realpolitik" as a means of convincing leaders of the various Italian nation states to unify. Otto von Bismarck, the first chancellor to King Wilhelm I of Prussia, used the military might of the Prussian armies to coerce other German states to unify under one German nation. This is perhaps the most oft-cited example of "realpolitik" in 19th-century European history.
4 The Dark Side of Nationalism

Less positive factors also contributed to nationalist unity throughout Europe during the 19th century. The impulse toward national unification often led to increased xenophobia and the establishment of right-wing groups with substantial political power. In Germany, for example, antisemitism remained a significant problem during the late 19th century. Despite the relatively tolerant attitude toward assimilated Jews following Bismark's unification of the country under Prussia, there was a significant increase in political antisemitic groups. Jewish citizens of Germany, and particularly Jewish immigrants to Germany who had yet to assimilate, were often blamed for various national crises that plagued the newly unified Germany. This led to the establishment of the antisemitic "völkisch movement," which would greatly influence the rise of National Socialism in Germany following World War I.