This paper concerns questions which elements of the biography of Jan Karski correspond with patterns useful for contemporary Polish diplomat. Conventional civil service career or patterns and norms  beyond the  practice and routine but to serve another man and Homeland?  Young Kozielewski started  his adventure in foreign service in 1936 from trainee in the Polish Consulates in Germany and Romania. Then couple months worked in the International Labor Office in Genève in 1937. Since January 1939  becomes referendary (law clerk) in the Consular Department of MFA, where he uses his Geneve’s experience concerning migration policy. Few weeks before the IIWW outbreak got promotion to the rank of III secretary in the Personal Office, where legendary Tomir Drymmer was his chief. That short diplomatic career turns into the beginning of his maturation, of his presence within dramatic, heroic war events. Karski was a very special diplomat.  Messages, pictures, documents and notes about situation in occupied Poland recorded, enrolled in his own memory  to bring them to western world. He witnessed Holocaust and saved the detailed story of fate of Jews for western leaders to inform them what’s happening with Jewish community under Nazi occupation.  In the end of the War he decided to write his testimony – story of the secret state. When the fate of Poland was decided and sealed by Allies Karski became an inconvenient witness of the truth. Removed from positions and cut off from the career path he made up his mind to start his academic way. Used the opportunity at Georgetown University in a short term got his Ph.D. and became one of the famous professors in the history of that school. Diplomatic career turned for effective diplomacy of historical memory.