On July 5, Slovakia celebrates a public holiday - the Day of Saints Cyril and Methodius. One of the important pages in the history of Slovakia is connected with the names of these saints and their great mission to Great Moravia (part of Great Moravia was also located on the territory of present-day Slovakia). The great mission contributed to the strengthening of the Christian faith among the Slavic peoples, made an invaluable contribution to the development of their culture. The names of Cyril and Methodius are associated with the invention of one of the first Slavic alphabets, with the help of which Slavic translations of liturgical books were recorded.