Question: Princess Frederica Dorothea "Louise" Philippine of Prussia, was a member of the House of Hohenzollern, and was a niece of which King of Prussia from 1740 until 1786, the longest reign of any Hohenzollern king?
Sentence (from "Princess Frederica Wilhelmina of Prussia"): By her marriage to Leopold IV, Duke of Anhalt-Dessau, she would become Duchess consort of Anhalt-Dessau.
Relevant evidence: No