Complex sentence: This belief, termed "Żydokomuna", was fuelled by the fact that two of the three Communist leaders who dominated Poland between 1948 and 1956, Jakub Berman and Hilary Minc, were of Jewish origin.
Split into simpler sentences: This belief, termed "Żydokomuna", was fuelled by fact that Poland's postwar Communist government was Jewish-dominated. Two out of three communist leaders who dominated Poland between 1948 and 1956 (Jakub Berman and Hilary Minc) were of Jewish origin.