Frederick II of Prussia
When Frederick ascended the throne as "King in Prussia" in 1740, Prussia consisted of scattered territories, including Cleves, Mark, and Ravensberg in the west of the Holy Roman Empire; Brandenburg, Hither Pomerania, and Farther Pomerania in the east of the Empire; and the former Duchy of Prussia, outside of the Empire bordering the Polish-Lithuanian Commonwealth. He was titled King in Prussia because this was only part of historic Prussia; he was to declare himself King of Prussia after acquiring most of the rest in 1772.