Hartog was the son of Jacob Porcelijn and Jansje Vreeland. In the 1930s, Hartog worked at the the Bijenkorf (a department store) as an office clerk, and later at Strengholt (a publishing company). He was also a dance teacher and a skilled piano player. He may have had a dance school or bookshop. Hartog married a non-Jewish woman on 3 January 1940. In 1943 he went into hiding, but in 1944 he was be…