With the advent of nationalism in the nineteenth century, intangible cultural heritage such as folklore and folk customs acquired immense significance as the foundational script for the revival of national identities - albeit interpreted, in many cases, through an intensely romantic hermeneutical lens. This period saw the advent of both folklore-collecting and comparative mythology, as well as the fashioning of new mythologies by authors such as Teodor Narbutt, Friedrich Kreutzwald, and Andrejs Pumpurs. Furthermore, in the 1870s, a movement among the Mari people of the Volga actually revived a form of Mari traditional religion and rejected Christianity, anticipating the twentieth-century ‘pagan revivals’ of native faith movements that would take place in many eastern European nations. This chapter examines nineteenth-century perceptions of ‘paganism’, as well as the ways in which the projection of ideas formed in this period onto the past has distorted the historiography of the final phase of Europe’s pre-Christian religions.