After the death of Frederick in 1786, Henry hoped to become more influential in the Prussian government as the advisor of his nephew, the new King Frederick William II of Prussia.
Although he was less influential than he hoped, Henry was more important during the last years of his life in advising King Frederick William III, who began his reign in 1797.
 Voltaire had seen in Frederick the embodiment of his "Philosopher King".
Arguably, Henry was by deed the man Voltaire had hoped the "Age of Reason" would produce.

Henry died at Rheinsberg Palace.
After the death of Frederick in 1786, Henry hoped to become more influential in the Prussian government as the advisor of his nephew, the new King Frederick William II of Prussia. Although he was less influential than he hoped, Henry was more important during the last years of his life in advising King Frederick William III, who began his reign in 1797.  Voltaire had seen in Frederick the embodiment of his "Philosopher King". Arguably, Henry was by deed the man Voltaire had hoped the "Age of Reason" would produce.
Henry died at Rheinsberg Palace.
Prince Henry of Prussia (1726–1802)