Joseph Mann was born on June 6, 1922 in Berlin to Sophia-Zissel and Mordechai-Marcus. His father, a committed Jew in the East European tradition, died when Joseph was young.
In 1939, after his mother and sister immigrated to the United States, Joseph made aliya. He decided on an agricultural life and for two years lived on Kibbutz Hasharon (Ramat David) and then on Maaleh Hachamisha and in Hadera. Afterwards he moved to Gezer where he oversaw field crops and indulged in sculpture and painting, illustrating a number of sections of the Passover Hagaddah.
Gezer was located near the Ramleh-Latrun Road, and the Arab Legion forces saw it as a threat which had to be eliminated. On June 10, 1948, a company of the Arab Legion, various irregular forces and armored vehicles attacked the kibbutz and captured it. Joseph fell in this battle, together with his girlfriend, Naomi. He was buried in the Gezer Cemetery.