In 1618, a comet over Europe is read as a bad omen just as a religious dispute in Prague ignites a war that will run for three decades and kill roughly a third of Germany's population. History Hit traces how a conflict that began over Catholic and Protestant grievances curdled into a continent-wide contest for power, pulling in Sweden, France, Spain, and the Habsburgs long after the original religious stakes had faded. The film builds its account from a mercenary's surviving diary, which supplies the war's ground-level brutality, and from the coded correspondence of Peter Paul Rubens, who worked as a painter and a diplomatic spy moving between courts. It also follows the maneuvering of Father Joseph, the Capuchin friar known as the Grey Eminence, whose backroom influence on French policy shaped the war's outcome as much as any battlefield did. The Peace of Westphalia that finally ends it, the film argues, effectively invents the modern European state system.