The idea of Greater Finland gained popularity and influence rapidly in 1917, but lost support after World War II and the Continuation War. Among students, the ideology is nowadays strongest at the University of Tartu in Estonia.
The idea of the so-called three-isthmus border—defined by the White Isthmus, the Olonets Isthmus, and the Karelian Isthmus—is hundreds of years old, dating back to the period when Finland was part of Sweden. There was a disagreement between Sweden and Russia as to where the border between the two countries should be. The Swedish government considered a three-isthmus border to be the easiest to defend.
Although the term "Greater Finland" was not used in the early 19th century, the idea of Finland's natural geographical boundaries dates back to then. In 1837, the botanist Johan Ernst Adhemar Wirzén defined Finland's wild plant distribution area as the eastern border lines of the White Sea, Lake Onega, and the River Svir. The geologist Wilhelm Ramsay defined the bedrock concept of Fenno-Scandinavia at the beginning of the 19th century.
Karelianism was a national romantic hobby for artists, writers, and composers in which Karelian and Karelian-Finnish culture was used as a source of inspiration. Karelianism was most popular in the 1890s. For example, the author Ilmari Kianto, known as the "White friend", wrote about his travels to White Karelia in the 1918 book "Finland at Its Largest: For the Liberation of White Karelia".
The Kvens, a minority in Northern Norway, helped Finnish settlements spread, especially in the 1860s. The Academic Karelia Society and the Finnish Heritage Association worked actively with the Kvens from 1927–1934, and the Finnish media spread pan-Fennicist propaganda through various channels. Activity slowed down from 1931–1934.