Question: Who is Peter August, Duke Of Schleswig-Holstein-Sonderburg-Beck's paternal grandfather?
Sentence (from "Frederick Louis, Duke of Schleswig-Holstein-Sonderburg-Beck"): Frederick Louis of Holstein-Sonderburg-Beck (6 April 1653 – 7 March 1728) was a Duke of Schleswig-Holstein-Sonderburg-Beck and field marshal of the Prussian Army.
Relevant evidence: No