Dorothea von Salviati's father-in-law was born on what date?
Dorothea von Salviati Dorothea von Salviati (1907–1972), was the wife of Prince Wilhelm of Prussia, the eldest son of Crown Prince Wilhelm, the eldest son and heir of the last German Emperor, Wilhelm II.
Frederick Augustus I of Saxony Frederick Augustus I (full name: "Frederick Augustus Joseph Maria Anthony John Nepomuk Aloysius Xavier"; German: "Friedrich August Josef Maria Anton Johann Nepomuk Alois Xavier" ; Polish: "Fryderyk August Józef Maria Antoni Jan Nepomucen Alojzy Ksawery Wettyn" ; 23 December 1750 – 5 May 1827) was King of Saxony (1805–1827) from the House of Wettin. He was also Elector Frederick Augustus III ("Friedrich August III.") of Saxony (1763–1806) and Duke Frederick Augustus I (Polish: "Fryderyk August I" ) of Warsaw (1807–1813).