Arturs Medveckis’ doctoral thesis in pedagogy in the subfield of general pedagogy “Kārlis Rūdolfs Kreicbergs and His Age: Identity in Pedagogue’s Life Activity” has been developed under the supervision of professor Dr. paed. Alīda Samuseviča at the Institute of Educational Sciences of Liepāja University from 2002 until 2016. The aim of the doctoral thesis: to research Kārlis Rūdolfs Kreicbergs’ (1921–2014) diverse identities in his pedagogical life activity through the approbation of the pedagogue’s identity model based on theoretical findings. Topicality of the empirical study and the research problem have been set forth in the introduction of the doctoral thesis, the aim and objectives have been formulated, the research design, structure, methods, procedure, and also resources and their selection have been described. The first part of the doctoral thesis includes the reflection of Kārlis Rūdolfs Kreicbergs as a pedagogue and choir conductor’s life activity from the study of biographical sources: life stories and interviews with K. R. Kreicbergs and his contemporaries, and also his family members; documentary evidence of his life history. An in-depth study has been continued in the second part of the doctoral thesis. Theoretical ideas on identity have been integrated in the theoretical model of the pedagogue’s personality and identity as elaborated by the author of the thesis. The model has been applied in the study on the narrative to identify the regularities in the development of personality, identity formation and consolidation; also, in the analysis and interpretation of certain time period and cultural environment. The final part of the doctoral thesis summarizes the most important conclusions about the empirical study, and the suggestions about similar studies on other cultural environments and/or other personality identities and their influencing factors for more advanced research have been made.