This study examines the role which the Cyril-Methodius tradition played in the 19th and early 20th century in religious, national and political developments in Moravia. It takes as its starting point Masaryk's criticism of the Young Czechs' demand for the introduction of a Slavonic liturgy. It tries to answer the question of whether this criticism was justified, whether it had a wider relevance than merely that of the historical period and whether it was also relevant for Moravia. The study shows that throughout the 19th century the Cyril-Methodius idea was used both by the church (unionism) and by national and political groups and even political parties. The Moravian Young Czechs used their demand for Slavonic worship, albeit unsuccessfully, in the election campaign against the Catholic parties in 1900–1901. Masaryk's criticisms proved to be justified and to a certain extent were even prescient, as Masaryk gave supporters of political Catholicism the right to use the Cyril-Methodius idea, and following their establishment Moravian Catholic parties fully adopted this idea.