On May 13, 1886, Natan Graubart was born in Płock – he was the chairman of the Talmud-Torah religious school committee, a merchant, owner of a seed store and the president of the Cooperative Loan Bank in Płock. Natan Graubart was also the treasurer of the local branch of the Society for the Promotion of Professional and Agricultural Work among Jews “ORT”, which was established in Płock in 1938. “ORT” organized tailoring courses for men and women, courses for shoe makers as well as knitting, underwear and corset manufacturing courses.
Natan Graubart was born in the family of Szyja and Sura Ryfka née Luszyński. His first wife was Chaja aka Helena née Landau (1891-1920), with whom he had two daughters: Jadwiga (born on September 23, 1918) and Zofia (born on December 16, 1919). In 1925 he married Cyrla aka Czesława Bruzda (born 1894). The couple had two sons – Saul Jehoszua (born January 14, 1927) and Aleksander (born March 24, 1930).