Why did Leopold von Ranke focus mainly on political history and relations between states?

Leopold von Ranke focused primarily on political history and the relations between states because he viewed states as "spiritual entities" and "original creations of the human mind," which he famously described as "thoughts of God".12

His historiographical approach was driven by the conviction that history was the unfolding of a divine plan, and he believed that the historian could discern intimations of this plan by intuiting the cultural principle incarnated in each nation-state. For Ranke, history was a complex process of "historical life" that assumed its most effective and "real spiritual" form through the existence and tensions of great states.23

Furthermore, his focus was reinforced by the nature of his primary sources. Because he relied heavily on documents such as reports from embassies, memoirs, and diaries, his work naturally centered on the foreign relations, government systems, and administrative actions of these states. He believed that social and political principles must vary according to the characteristics of different peoples, leading him to prioritize the independent development of individual states over abstract, universally valid principles.231