ENWith a view to initiate their Counter-Reformation activities and found a college in Vilnius, the Jesuits began visiting Lithuania as early as in 1564. In 1570 the Jesuit college was founded in Vilnius, whereas the year 1579 was marked by the founding of Vilnius Jesuit Academy, i.e. the University. In due course, the following Jesuit teaching institutions were established: in 1616 a college in Kražiai, in 1649 a college in Kaunas, and in 1655 a college in Pašiauše. Afterwards, 1680 marked the establishment of the mission in Merkine, the year 1683 was noted for the establishment of the mission in Šeduva, whereas 1683 marked the founding of the mission in Karaliaučius. While settling in Lithuania, the Jesuits pursued two basic aims: on the one hand, by study and research, they were trying to fight the spreading of the Protestant Reformation in the country while, on the other hand, they were attempting to explain the basic truths of the Catholic faith to ordinary people in their native tongue. Alongside their pedagogic activity, the Jesuits were also deeply involved in missionary pursuits. It was in 1576 that, following the invitation of Bishop Merkelis Giedraitis, two missionaries arrived in Samogitia. With time their number grew, and so grew the area of their activities. The missionaries, while communicating with local inhabitants and explaining to them the truths of the Catholic faith, had to know the Lithuanian or Samogitian language. For that purpose the teaching programmes at Vilnius University were revised, and additional academic lessons (academiae), purposing to teach the Lithuanian language, were introduced. While analysing the yearly accounts, obituaries, personal catalogues etc., we can get a very clear view of the number of Lithuanian preachers at that time as well as of the character of their activities.We can also very well understand their role in perfecting the Lithuanian language and in strengthening its importance in the public life of Lithuania between the 16th and the 18th centuries. The Jesuits mostly contributed towards the preparation and printing of Lithuanian books in the Grand Duchy of Lithuania, for example of Dauksza’s Catechism, published in 1595, and Dauksza’s Postilla Catholica, published in 1599. It should also be noted that every Jesuit college could pride itself on a library, containing from several hundred to several thousand volumes. Literary competitions as well as theatrical performances were organised. Local people and other laymen are known to have participated in those events. All the above mentioned facts testify to the importance of the Jesuit activities for the culture of particular regions, and emphasise the contribution of those activities towards the way in which that culture developed. [From the publication]