The overall aim of this study is to discuss the problems historians working in universities under the communist regime had to face. Probably the main challenge was the interwoven periods of tightening and loosening of restrictions. There were the changing relations with the censors office, problems with getting permission to go abroad to study in archives and take part in conferences. Analyzing the influence under which the academics worked we obtain a better understanding of the reasons for decisions taken by them in relation to their scientific carrier. Notwithstanding this difficulties the non party academics, like professor Czapliński, struggled to have a say in both didactic and scientific life of the University, upholding at the same time their own high ethical standards. He considered himself responsible for the place the Wrocław University had on the academic map of Poland, to which end he was as active as conditions allowed him. The study is based on the correspondence with two eminent Polish historians professors Adam Kersten and Henryk Wereszycki confronted with the records in the Diary of professor Czapliński.