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 Louise of Prussia (1770–1836)"): Princess Frederica Dorothea "Louise" Philippine of Prussia (24 May 1770 - 7 December 1836) was a member of the House of Hohenzollern.
Relevant evidence: No