The two sonatas presented here as well as the two compositions of the Czech composer Janacek were all written during a period of about 25 years only (1883 till 1910). The present four contributions to cello literature are exceptions, from a formal perspective, and above all judged by their content, as examples of a serious development within romantic bounds. All of these sonatas something in common: they are, seen from within the entire œuvrs of these composers, each individual works which are, at the same time, exemplary studies of remarkable uniqueness.