Among them was the famous Armenian composer Komitas, Hrachya Acharyan and the controversial Communist revolutionary Stepan Shahumyan as well as others who became famous later on. The most famous donation made by Mantashev remains the Armenian Church of St. John the Baptist in Paris on Jean Goujon street.
He donated 300,000 rubles towards the building of the Nersessian spiritual academy. He donated 250,000 rubles to the holy town of Echmiadzin for the building of the residence of the Catholicos of All Armenians (construction completed in 1914).