Short answers, pulled from the story.
Romantic nationalism holds that a state's political legitimacy derives organically from the unity of the people it governs, based on shared language, race, ethnicity, culture, religion, and customs. It arose in reaction to dynastic or imperial legitimacy, which located authority in a monarch or ruler rather than in the people themselves. It can be applied to both ethnic and civic nationalism.
The watershed year for romantic nationalism in Europe was 1848, when a revolutionary wave spread across the continent. Numerous nationalist revolutions occurred in fragmented regions such as Italy and multinational states such as the Austrian Empire. Although the revolutions initially fell to reactionary forces, they marked the first step toward the formation of modern nation states.
The Brothers Grimm collected fairy tales under the belief that such stories, if uncontaminated by outside literary sources, had been preserved in the same form across thousands of years and expressed the primordial nature of a people. They rejected tales resembling those of French writer Charles Perrault as insufficiently German, and altered language throughout, changing "Fee" to enchantress or wise woman and "prince" to "king's son". Their approach influenced collectors including Russia's Alexander Afanasyev, the Norwegian pair Peter Christen Asbjornsen and Jorgen Moe, and Australia's Joseph Jacobs.
A performance of Auber's La Muette de Portici in Brussels in August 1830 sparked a riot that ignited the Belgian Revolution of 1830-31, recognized as the first successful revolution in the model of romantic nationalism. The opera set a doomed romance against a backdrop of foreign oppression, and its themes resonated immediately with the political moment.
Adam Mickiewicz developed the idea that Poland was the Messiah of Nations, predestined to suffer as Jesus had suffered in order to save all of humanity. He expressed this vision in his patriotic drama Dziady, which depicted Poland as the Christ of Nations, and in Books of the Polish Nation and Polish Pilgrimage. He wrote that Poles were destined to teach civilization to foreigners rather than learn it from them.
Nazi chief ideologue Alfred Rosenberg described German Romanticism as welcome as rain and argued it needed to be followed to its racial core. On the 8th of May 1933, two days before the Nazi book burnings in Berlin, Joseph Goebbels told theatre directors that German art would be heroic, Romantic, and non-sentimental, or it would be nothing. The Soviet scholar Naum Berkovsky described the process as extracting Romanticism from the past and absorbing it into Nazi ideology after cleansing it on racial grounds.