Blessed Karl Leisner
February 28, 1915, Rees, Germany-August 12, 1945, Dachau
He studied theology in Munster, and tried to establish Catholic youth groups. However, the Nazis sought control of all work with youth, and he had to take teenagers “camping” in Belgium and the Nederlands in order to freely discuss Catholicism.
He spent six months in compulsory agricultural work during which, despite Nazi opposition, he organized Sunday Mass for his fellow workers. His home was raided by the Gestapo, who seized his diaries and papers. These meticulously preserved documents tell how the spiritual young man became a heroic religious leader.
Ordained deacon by Bishop von Galen in 1939. Imprisoned in Freiburg, Mannheim and Sachsenhausen for criticizing Hitler. Transferred on 14 December 1941 to Dachau, where he was secretly ordained on 17 December 1944 by French bishop Gabriel Piquet, who had been admitted to the camp with the help of local religious authorities. Leisner was so sick he had to postpone his first Mass for over a week.
Still in the camp when it was liberated on 4 May 1945, but was immediately transferred to tuberculosis sanitarium of Planegg, near Munich for the remaining months of his life.
Saints of the Faith has a great post on Blessed Karl, with additional information about his ordination in Dachau and one of his ordination cards.