The article discusses events from 1706 to 1709, associated with the Great Northern War in the Polish-Lithuanian Commonwealth, focusing on the reign of Stanisław Leszczyński and the role of Stanisław Antoni Szczuka by the king’s side. Primary sources include the correspondence of Lithuanian Grand Chancellor Karol Stanisław Radziwiłł (1669-1719), particularly letters from royal secretaries Samuel Kazimierz Szwykowski and Jozafat Michał Karpi, which document daily events of the war in the Commonwealth. These letters were published in two volumes by Jerzy Dygdała in 2018 and 2019 and include information from contemporary newspapers, excerpts from Radziwiłł’s diary, and an attributed account of the king’s journey to Saxony by Szczuka. Additional sources feature correspondence between Stanisław Antoni Szczuka and his wife, Konstancja Potocka Szczuka, as well as court expenses from this period. During Leszczyński’s reign, Szczuka served as an advisor and royal minister, overseeing the royal chancellery, preparing documents for the monarch’s signature, and receiving diplomatic missions. The letters of Szwykowski and Karpi reflect Leszczyński’s trust in Szczuka, who was known for his wisdom, dedication to the Commonwealth, and advocacy for national unity. Renowned for his oratory skills, Szczuka expressed skepticism toward the political and military plans of Charles XII and disapproved of the Swedish army’s conduct in the Commonwealth.