 Many of Duke Peter's compositions were used as educational tools by the Saint Petersburg Conservatory.The composer and teacher Adolf Henselt, a close friend of the Duke's, expanded on many of his compositions in order to utilize them for instructional purposes.Peter spent fifty years in Russia's service, for which he was widely respected and was thanked by a massive celebration in St Petersburg in 1880 attended by his first cousin Tsar Alexander II of Russia and most of the Imperial family, his cousin Grand Duke Nicholas of Oldenburg and representatives of the many organizations with which the Duke was connected.