Abstract
The study by István Janek about Soviet diplomacy and the development of the Slovak-Hungarian relations in years 1939-1940 is devoted to the segment of Slovak-Hungarian relations, which is really is not a usual part of current historical research in the Slovak Republic (certainly not in the Czech Republic), although it is a substance, as author of the study presents, in many respects, raises the interesting aspects of international policy (active policy of the Soviet Union in the region under the hegemony of Hitler's Germany).