Augustus, Hereditary Grand Duke of Oldenburg

Augustus, Hereditary Grand Duke of Oldenburg (also known as Frederick Augustus von Holstein-Gottorp) (born February 2, 1879 - died January 5, 1942) was the last heir apparent to the Grand Duchy of Oldenburg as the eldest son of Grand Duke Frederick Augustus II and his first wife, Princess Elisabeth Anna of Prussia, He was created Hereditary Grand Duke of Oldenburg following the accession of his father in 1900 until the abolition of the monarchy in 1918; He became a pretender to the Grand Ducal throne following the death of the father in 1931 until his death in 1942 when he was succeeded by his younger half-brother Nikolaus as a pretender. He married Princess Sanna of Sweden and had one daughter, Duchess Charlotte of Oldenburg. He is also the twin brother of Duchess Sophia Charlotte of Oldenburg, the ex-wife of Prince Eitel Friedrich (a son of German Emperor Wilhelm II and German Empress Augusta Victoria).