Jooseppi Julius Mikkola graduated from the Hämeenlinna lyceum upper secondary school, where he had gained an interest in languages from being a student of Arvid Genetz. He entered the Imperial Alexander University to study Sanskrit and comparative linguistics in 1886. The hallmarks of J. J. Mikkola’s career were wide-ranging language research and the Fennoman cause which came out of Hämeenlinna city.

Soon after starting his studies, Mikkola began to assist Emil Nestor Setälä with proofreading dissertations and this is how he became acquainted with Finno-Ugric linguistics. Mikkola, however, was selected for a position in Slavic Philology. This choice was most likely influenced by the numerous study trips he made to Russia and the Baltic countries. Learning languages was easy for Mikkola. He acquired a broad understanding of different languages through his study trips to various language areas and this learning showed in his research.

Mikkola finished his Bachelor’s degree in 1889. Four years later he produced the work which constituted his dissertation, a study on the similarities between Slavic languages and western Finnish dialects (Berührungen zwischen den westfinnischen und slavischen Sprachen, 1893). For the next five years Mikkola’s research attracted a lot of attention from philologists and he was named Extraordinary Professor of Slavic Philology in 1900. After that the post was made permanent and Mikkola was the professor from 1921–34.

Mikkola’s main work, Urslavische Grammatik (‘A Proto-Slavic Grammar’), appeared in 1913. By then Mikkola had already become one of the leading Slavic philology researchers in the world. He was offered posts in places such as the University of Leipzig, where he had done research from 1896–97, but he decided to stay in Helsinki.

Mikkola focused on specific issues and problems of language in his research. He did not write so many general reference works, but he did translate a number of them into Finnish, such as Vasily Kluchevsky’s A History of Russia (1910). In addition to studying languages, Mikkola researched history and literature. He was also the long term chair of the Military Language Committee and he participated in the drafting and publication of the Finnish Military Dictionary.

Mikkola was a pro-Finnish professor, but he did not participate in politics in the same way that many of his contemporaries did. Instead he belonged to the Fennoman movement. He actively participated in, among other things, the debate on the genetic race of the Finnish-speaking population of Finland. In his publication Olemmeko mongoleja? (‘Are we Mongols?’), Mikkola strongly opposed the long held notion that Finnish-speaking Finns were a genetically inferior race to Swedish-speaking Finns, an idea which people such as Axel Olof Freudenthal had adopted at the end of the 1800s. Mikkola was also elected as the first chair of the Association of Finnish Culture and Identity in 1906.

Mikkola was said to have been an inspiring lecturer. He also spread his knowledge in the auditoriums and outside his office by actively participating in students’ activities. Mikkola and his wife Maila Talvio’s home was a meeting place for writers, scientists and hundreds of students.