The first work dedicated specifically to "just war" was "De bellis justis" of Stanisław of Skarbimierz (1360–1431), who justified war by the Kingdom of Poland with Teutonic Knights. Francisco de Vitoria criticized the conquest of America by the Kingdom of Spain on the basis of just war theory. With Alberico Gentili and Hugo Grotius just war theory was replaced by international law theory, codified as a set of rules, which today still encompass the points commonly debated, with some modifications. The importance of the theory of just war faded with the revival of classical republicanism beginning with works of Thomas Hobbes.