Scandinavism (; ; ), also called Scandinavianism or pan-Scandinavianism, is an ideology that supports various degrees of cooperation among the Scandinavian countries. Scandinavism comprises the literary, linguistic and cultural movement that focuses on promoting a shared Scandinavian past, a shared cultural heritage, a common Scandinavian mythology and a common language or dialect continuum (from the common ancestor language of Old Norse), and which led to the formation of joint periodicals and societies in support of Scandinavian literature and languages. Nordism expands the scope to include Iceland and Finland. The movement was most popular among Danes and Swedes. History According to historian Sverre Bagge, prior to the formation of state-like kingdoms in Scandinavia, Scandinavia was culturally and linguistically homogeneous. Even in the thirteenth century the term ‘Danish tongue’ was used for the language throughout the area. There were different dialects, but the lines of division between them did not correspond to the later national borders. Religion and customs were also similar, during the pagan as well as the Christian periods. Thus, no cultural or linguistic distinctions prevented unification of each country. Nor, on the other hand, did such distinctions give rise to natural borders between the kingdoms that eventually emerged.Pan-Scandinavianism as a modern movement originated in the 19th century, but the movement had already begun spreading a century earlier in circles of literature and science. The Pan-Scandinavian movement paralleled the unification movements of Germany and Italy. As opposed to the German and Italian counterparts, the Scandinavian state-building project was not successful and is no longer pursued. It was at its height in the mid-19th century and supported the idea of Scandinavian unity. The movement was initiated by Danish and Swedish university students in the 1840s, with a base in Scania. In the beginning, the political establishments in the two countries, including the absolute monarch Christian VIII and Charles XIV with his "one man government", were suspicious of the movement. The movement was a significant force from 1846 to 1864, however the movement eventually dwindled and only had strong support among the Swedish-speaking population of Finland. The collapse of Pan-Scandinavianism came in 1864 when the Second Schleswig-Holstein War broke out. King Karl XV of Sweden (who was also King Karl IV of Norway), who reigned from 1859 until his death in 1872, in spite of championing Pan-Scandinivianism, failed to help Denmark in the war. Author Hans Christian Andersen became an adherent of