In communist Yugoslavia, research on Byzantium became institutionalised already in 1948 with the setting up of the Belgrade-based Institute of Byzantinology (Vizantološki institut) within the Serbian Academy of Sciences. Its thematic priorities, as before the war, were heavily tilted towards Byzantine-South Slav (especially Serbian) relations in the political, cultural and, increasingly now, socio-economic sphere. Compared to other branches of historiography and to the situation in Bulgaria and Romania, Yugoslav/Serbian medieval and Byzantine studies were less affected by doctrinaire Stalinism, while, already in the late 1940s, the communist leadership was encouraging Yugoslav historians to put Marxist historical theory to a more creative use. But if such a modicum of intellectual freedom helped sustain Byzantine research, its fecund development after the war owed everything to the Russian-born émigré byzantinist Georgiy Ostrogorski’s personal prestige and dedication to the growth of the ‘byzantinological’ field in Yugoslavia.