 He sponsored Mikalojus Daukša, who translated and published "Catechism" (1595) and "Postil" (1599) in the Lithuanian language—the first Lithuanian books printed within the Grand Duchy of Lithuania.He also supported Maciej Stryjkowski, author of the first printed history of Lithuania.In recognition of his efforts, Giedraitis is often referred to as the second baptist of Samogitia (the first official baptism of Samogitia took place in 1413–1417).