the Russian Olonets region. Important books such as the Bible and Code of Laws were only available in Latin, Swedish or a few other European languages such as French or German. The understanding of the medieval circulation of these non-Finnish writings in what is now Finland has been growing since the National Library of Finland digitised its medieval . Written Finnish was established by Bishop and Finnish Lutheran reformer Mikael Agricola (1510—1557), who based it mainly on western dialects. His main works are a translation of the New Testament (completed in 1548) and a primer, Abckiria, in Finnish. The first grammar of Finnish was published by Aeschillus Petraeus in 1649, and includes eight Finnish riddles. Another major step towards developing a written vernacular literature came with the work of Cristfried Ganander, who published over 300 riddles in 1783. Until 1800, most of the literature published in Finnish was religious. Nineteenth century After becoming a part of the Russian Empire, known as the Grand Duchy of Finland, in the early nineteenth century, Finland saw a rise in education, and nationalism promoted public interest in folklore and resulted in increasing literary activity in the Finnish language. This was characterised by an explosion in the collection and study of folklore in Finland, with a particular emphasis on Finnish-language material. Much of this material is widely thought to originate in the Middle Ages, and is often thought of in Finland as medieval literature, although this is a problematic claim. Much also came from Karelia, which also being a part of Russia contributed to the creation of Finnish literature. These folklore-collecting efforts were to a large extent co-ordinated by the Finnish Literature Society, founded in 1831. Hundreds of old folk poems, stories and their like have been collected since the 1820s into a collection which is among the largest in the world. Many of these have since been published as Suomen kansan vanhat runot ('The Ancient Poems of the Finnish People'), a colossal collection consisting of 27,000 pages in 33 volumes. The prominence of folklore in nineteenth-century Finland made Finnish scholarship world-leading in that area at the time; thus for example the internationally used Aarne–Thompson classification system for folktale narratives originated in Finnish scholarship. The most famous collection of folk poetry is by far the Kalevala. Referred to as the Finnish "national epic" it is mainly credited to Elias Lönnrot, who compiled the volume. It