Who married Duke Peter of Oldenburg?

Duke Constantine Frederick Peter of Oldenburg (German: Konstantin Friedrich Peter; Russian: Пётр Гео́ргиевич Ольденбу́ргский, romanized: Pëtr Geórgievič Ol'denbúrgskij; 26 August [O.S. 14 August] 1812 – 14 May [O.S. 2 May] 1881) was a Duke of the House of Oldenburg. He was the grandfather of Duke Peter of Oldenburg and Grand Duke Nicholas Nikolaevich, General of the Imperial Russian Army during World War I. His great-great-grandson, Nicholas Romanov, was the President of the Romanov Family Association until his death in 2014.

Peter was a scholar and philanthropist. He was also noted composer of music. In 1857, he composed the music for Marius Petipa's ballet La Rose, la Violette et le Papillon. The Pas d'Esclave from the ballet Le Corsaire, which is taken from his score for this work, is still heard in theatres all over the world.

Princess Therese of Nassau-Weilburg (German: Therese Wilhelmine Friederike Isabelle Charlotte Prinzessin von Nassau-Weilburg; Russian: Терезия Васильевна Нассауская, Tereziya Vasilyevna Nassauskaya; 17 April 1815 in Weilburg, Duchy of Nassau – 8 December 1871 in Prague, Kingdom of Bohemia, Austria-Hungary) was a member of the House of Nassau-Weilburg and a Princess of Nassau-Weilburg by birth. Through her marriage to Duke Peter of Oldenburg, Therese was also a Duchess of Oldenburg.