ENThe problem of war, its nature, causes, justifcations and characters, together with their cultural, social, political and ethical evaluations, has a centuries-old tradition of research and refection. In this study of the issue, the author’s main interest lies in the broadly understood idea of war present in the theological, philosophical and historical refections of Piotr Skarga SI on the Christian and civic duty to care for the prosperity of the state and the good of all its inhabitants he presented in the pages of his writings. Keywords: Piotr Skarga, just war, unjust war.