The standards of treatment of prisoners and their legal protection have come a long way. The rights of prisoners did not always exist and were created gradually, together with the development of different prison systems and the development of human rights in general. The changes brought about by the reforms of the prison system are a reflection of the recognition of the importance of dealing with prisoners during and after the execution of the prison sentence, both by the profession and by society. Historical records of inhumane conditions in prisons during the 18th century and earlier, as well as the development of human rights, have changed the perception of them and their rights. The historical review of prison systems, which is the core of this paper, offers an insight into the dominant ideas about the purpose of punishment and the value of prisoners as human beings in certain periods and in certain areas. Through the review, it is possible to follow the development of standards of treatment of prisoners, key persons and states in that process, and examples of treatment that are commented on in terms of their compliance with today's Mandela Rules and the Convention against Torture and Other Cruel, Inhuman and Degrading Treatment or Punishment. The two mentioned documents, which are described at the very beginning, served in this paper as a reference point of the generally accepted rights of prisoners today, so that a comparison could be made with the inhumane history of their treatment and gradual progress. The aim of this paper is therefore to show the historical development of standards of treatment of prisoners based on the human rights of prisoners.