The brightest representatives of the national historiography of the 17th – 18th centuries are the so-called Cossack Chronicles. These texts, written by the Cossack elite of the Hetmanate, serve as an excellent historical source for exploring the historical and social and political thought of the epoch of Bohdan Khmelnytskyi. The writings of the Military Chancellerists are complex structures that are on the verge of history and literature, and the term Chronicles have been used by their first publishers. From the whole multiplicity of Cossack Chronicles, the most famous and original are the works of Eyewitness, H. Hrabianka and S. Velychko. The article shows the peculiarities of research and perception of these historical texts in the works of scholars of the mid-19th – beginning of the 20th centuries. The first scientific researches of Chronicles by their publishers, special studios of historians and literary critics on the phenomenon of creativity of Military Chancellerists are analyzed. The perception and use of Cossack Chronicles in writers are disclosed. Particular attention is paid to those works where Cossack historical and literary works are the main subject of research. The article shows priority subjects for the study of Cossack chronicles. Most of the research attention was given to the source studies of Cossack historical works. In particular the leading topics were the source value of the Chronicles, the structure of the works, the source base used by the historians of Hetmanate and the attempts to extract the original text from numerous copies later ones of the works. Scientists also investigated the attribution of Cossack Chronicles, the situation of the creation of works and the ideology of their authors. But mostly these topics will be leading for Soviet and contemporary Ukrainian historiography. The transformation in the perception of the 19th – beginning of the 20th centuries researchers of the literature of the Chancellerists – from sources of factual information to literary and fictional, heroic history are analyzed.