Question: Who is Princess Alexandrine Of Prussia (1842–1906)'s paternal grandfather?
Sentence (from "Prince Albert of Prussia (1809–1872)"): Two of Albert's elder brothers were Frederick William IV, King of Prussia from 1840 till 1861, and William I, King of Prussia from 1861 to 1888 and German Emperor from 1871 until 1888.
Relevant evidence: No