A new memorial center in Berlin pays tribute to the thousands of German who risked everything to save Jews from Nazi persecution and documents the years these "Silent Heroes" kept their Jewish guests hidden from the authorities.

The permanent museum exhibition shows the persecution and the desperate situation of Jews facing the threat of deportation, how some of them decided to resist the threat to their lives by going underground, as well as the actions and motivations of the men and women who helped them. It documents not only successes in saving Jews, but also attempts that failed. Some 5,000 Jews in Germany were able to survive the war in hiding thanks to an unknown number of people who were involved in helping them. Research suggests that for each person in hiding, around 10 people were involved in aiding them. They found the courage to help as far as they could, despite the risk involved. Else Ackermann, a retired teacher, and her brother Hans, a former municipal civil servant, were two of these.

In 1942, at the age of 53, Johanna Putzrath was compelled to work as a forced laborer in a firm in Tempelhof in Berlin. She knew that Else Ackermann and her brother Hans, who were devout Protestants and adherents of Rudolf Steiner's spiritual philosophy, had offered help to another Jewish worker at the firm. When this woman was unexpectedly deported, Johanna Putzrath turned to the Ackermanns.  Without hesitating, Hans Ackermann took the unknown Jewish woman into his two-roomed apartment in Tempelhof. His sister Else, who lived in Steglitz, joined him in helping the refugee Johanna Putzrath.

At the end of January 1943 Hans Ackermann also gave shelter for over a month to a married couple, Ines and Max Krakauer, until they found other places to stay in southern Germany. Even when the Ackermanns' apartments were destroyed by bombs in 1944, they moved, yet they continued hiding Johanna Putzrath. After almost two-and-a-half years, the three of them witnessed the end of the war together.

Johanna Putzrath emigrated to the USA and lived in New York until her death in 1975. Else Ackermann died in the 1940s in Berlin; her brother Hans died in 1959.

Visit the Memorial's English website at www.gedenkstaette-stille-helden.de/english Read more about the Memorial's stories in the UK Guardian. (Photo: Johanna, left, with Else, who saved her from persecution)