 Hagemeister served as researcher at the Department of History of the University of Basel and as temporary professor at the Department of History of Ludwig Maximilian University, Munich and at the Department of East European History at Viadrina European University, Frankfurt (Oder).Hagemeister wrote his doctoral thesis on the Russian philosopher Nikolai Fyodorov (1829–1903).In his current research he concentrates on the origins and early history of "The Protocols of the Elders of Zion" and the life and work of the Russian religious and apocalyptic writer Sergei Nilus (1862–1929).