Opole Region occupied a most significant place in the studies conducted by Kazimierz Orzechowski, who took part in the action of securing archival acts of Opole Regency after the War. The Polish school system in Silesia was the subject of his doctoral dissertation. He paid a lot of attention to the legal situation of peasants in Opole Region in the 19th century. He was also one of the co-founders of Studia Śląskie. Seria nowa (The Silesian Studies. A New Series) and the Silesian Institute in Opole. For many years he cooperated with The Silesian Studies and Opole Quarterly. Apart from the research into the history of Opole Region, K. Orzechowski also made a great contribution to the development of Opole historical centre. He was the founder and the first Head of the Chair of History at Teacher’s Training College in Opole. He worked for almost twenty years there. He was a supervisor and reviewer of doctoral dissertations and works submitted to obtain professor’s degree by research workers at the College, as well as a member of the board in charge of conferring the professor’s degree.