The son of Clara and Sally Grün, Rabbi Iwan Gruen (1900-1981) grew up in Berlin, Germany. He attended the College for Jewish Studies, and, in 1923, received a doctorate in philosophy from Humboldt University, where he studied under Dr. Leo Baeck. He was ordained by the Hochschule fur die Wissenschaft des Judentums in Berlin in 1925.
After serving a small congregation in Frankfurt for two years, Rabbi Gruen became the Chief Rabbi of the Free City of Danzig in 1928. The synagogue he led there had more than 10,000 members and was one of the largest in Europe. He was the president of the Danzig B’nai B’rith, represented Danzig minority groups before the League of Nations, and was a member of the World Union for Progressive Judaism.
By 1939, the congregation was forced to sell the Great Synagogue of Danzig. A few ritual objects were saved and sent to the Jewish Theological Seminary in New York for safekeeping. The proceeds of the sale enabled some members to emigrate. After the Gestapo had arrested Rabbi Gruen three times, threatening him with imprisonment, he, his wife, Gertrude, and their daughter, Hanna, were also able to leave.
“There can be no doubt that governments and their leaders who are responsible for bringing war, suffering and destruction upon the world must be brought to justice,” he wrote in 1944. “But justice does not mean vengeance. Justice is an educational measure which regulates the moral and ethical relations between man and man, between nation and nation. Education for justice, tolerance, humanity, brotherhood and goodwill should be the method with which we ought to approach the peoples who are our enemies today.”
Rabbi Gruen led congregations in Wisconsin and Illinois before joining Temple Israel in New Castle in October 1945. He stayed with the congregation for the rest of his life. While in New Castle, Rabbi Gruen was the president of the Nathan J. Love B’nai B’rith Lodge and was active in many Jewish and interfaith service organizations and activities. Rabbi Gruen gave his final sermon on February 27, 1981, just a week before his death.
Hanna Gruen started one of the first occupational therapy practices in Pittsburgh and became the director of the Occupational Therapy Department at St. Margaret Hospital.