Understanding both the history of the discipline you are interested in and understanding the cultural, political, and social era of the particular text you are studying depends on reading and knowing history. History’s major activity is to gather evidence regarding the past, evaluate that evidence within the temporal scope of the period under study, and then access how that evidence contributes to our understanding of that period.
Historical research relies on a wide variety of sources, primary and secondary and oral tradition.
Are scholarly interpretations and critiques of the historical period of interest that you are studying. In the study of modern history the difference between primary and secondary sources are usually clear. In ancient and medieval history this distinction is not so clear.