Despite all of his wealth Mantashev led a modest lifestyle. He did not like gold and never wore jewellery. He only attached a fresh flower to his vest. He did not have an entourage and enjoyed traveling by tram in Tiflis. It is said that Mantashev only carried with him 20 gold coins and five rubles. Mantashev loved the theater. In Tiflis he built the Pitoewski Theater (now the Rustaveli Theater). In the Academie National de Musique of Paris he had a personal lounge. He intended to build a similar theater in Yerevan. The Small Hall of the Armenian Philharmonic Orchestra was also built by him. Mantashev died on 19 April 1911 in Saint Petersburg. His body was moved to Tiflis and buried next to his wife at the cemetery of Vank Cathedral which was being restored at the time with his donations. After the October Revolution of 1917, his company ceased to exist along with all the other oil companies in Russia. In 1933, by the order of Lavrentiy Beria, the Vank Cathedral was destroyed along with the cemetery where Mantashev was buried. Today he is remembered in Tbilisi for his charity, where many of his buildings are still standing, and in Yerevan, where a downtown street was named after him along with a major luxury goods store. A monument of Mantashian has been erected in Yerevan in April 2012.
