The Swiss-Russian economist Nikolaj Sieber was one of the first who wrote about Marx in Russia. In this article we reconstruct the development of his thought by mobilising evidence about the intellectual and political context he lived in. We document his involvement within the Ukrainian national movement of the 1870 s and argue that this closeness was consistent with his take on the capitalist evolution of the Russian Empire. We discuss his importance in the Russian debates on the future of the peasant commune and of Russia and conclude that his interpretation of Marx and capitalism was crucial for the development of the Russian social-democratic party.