Even before the era of the French Revolution, the seeds of nationalism were planted in the hearts and minds of many Europeans as an aspect of the Romantic movement. Romanticism was not a political movement – it was a movement of the arts. It emerged in the late eighteenth century and came of age in the nineteenth. Its central tenet was the idea that there were great, sometimes terrible, and literally “awesome” forces in the universe that exceeded humankind’s rational ability to understand. Instead, all that a human being could do was attempt to pay tribute to those forces – nature, the spirit or soul, the spirit of a people or culture, or even death – through art.
The central themes of romantic art were, first, a profound reverence for nature. To romantics, nature was a vast, overwhelming presence, against which humankind's activities were ultimately insignificant. At the same time, romantics celebrated the organic connection between humanity and nature. They very often identified peasants as being the people who were "closest" to nature. In turn, it was the job of the artist (whether a writer, painter, or musician) to somehow gesture at the profound truths of nature and the human spirit. A "true" artist was someone who possessed the real spark of creative genius, something that could not be predicted or duplicated through training or education. The point of art was to let that genius emanate from the work of art, and the result should be a profound emotional experience for the viewer or listener.
Quite by accident, Romanticism helped plant the seeds of nationalism, thanks to its ties to the folk movement. The central idea of the folk movement was that the essential truths of national character had survived among the common people despite the harmful influence of so-called civilization. Those folk traditions, from folk songs to fairytales to the remnants of pre-Christian pagan practices, were the “true” expression of a national spirit that had, supposedly, laid dormant for centuries. By the early eighteenth century, educated elites attracted to Romanticism set out to gather those traditions and preserve them in service to an imagined national identity.
The iconic examples of this phenomenon were the Brothers Grimm, Jacob and Wilhelm, who were both expert philologists and avid collectors of German folk tales. The Brothers Grimm collected dozens of folk (“fairy”) tales and published them in the first definitive collection in German. Many of those tales, from Sleeping Beauty to Cinderella, are best known in American culture thanks to their adaptation as animated films by Walt Disney in the twentieth century, but they were famous already by the mid-nineteenth. The Brothers Grimm also undertook an enormous project to compile a comprehensive German dictionary, not only containing every German word but detailed etymologies (they did not live to see its completion; the third volume E – Forsche was published shortly before Jacob’s death).
The Grimm brothers were the quintessential Romantic nationalists. Many Romantics like them believed that nations had spirits, which were invested with the core identity of their “people.” The point of the Grimm brothers' work was reaching back into the remote past to grasp the "essence" of what it meant to be "German." At the time, there was no country called Germany, and yet romantic nationalists like the Grimms believed that there was a kind of German soul that lived in old folk songs, the German language, and German traditions. They worked to preserve those things before they were further "corrupted" by the modern world.
In many cases, romantic nationalists did something that historians later called "inventing traditions." One iconic example is the Scottish kilt. Scots had worn kilts since the sixteenth century, but there was no such thing as a specific color and pattern of plaid (a "tartan") for each family or clan. The British government ultimately assigned tartans to a new class of soldier recruited from Scotland: the Highland Regiments, with the wider identification of tartan and clan only emerging in the first few decades of the nineteenth century. The point was instilling a nationalist pride in a specific group of military recruits, not celebrating an “authentic” Scottish tradition. Likewise, in some cases folk tales and stories were simply made up in the name of nationalism. The great epic story of Finland, the Kalevala, was written by a Finnish intellectual in 1827; it was based on actual Finnish legends, but it had never existed as one long story before.
The point is not, however, to emphasize the falseness of the folk movement or invented traditions, but to consider why people were so intent on discovering (and, if necessary, inventing) them. Romanticism was, among other things, the search for stable points of identity in a changing world. Likewise, folk traditions - even those that were at least in part invented or adapted - became a way for early nationalists to identify with the culture they now connotated with the nation. It is no coincidence that the vogue for kilts in Scotland, ones now identified with clan identity, emerged for the first time in the 1820s rather than earlier.