Johannes Coert was born in Hendrik Ido Ambacht on the 10th of August 1829, and died in Goedereede on the 3rd of February 1882, where he was established as a notary and since 1866 and for may years he was a member of the City Council. On the 16th of May 1867 in Nieuwe Tonge he married Maatje Zaaijer. She was born in Nieuwe Tonge on the 20th of December 1843, and died in The Hague on the 12th of February 1919. She was the daughter of Anthony Zaaijer and Dingena Vreeswijk. They had 8 children. Dingena Cornelia, Hendrik Jan (he was the second in line who worked on the “Geschiedenis van de Familie Coert”; On the 20th of June 1898 he was promoted to doctor in Leiden; he married Henrica Berest; she was born in Soerabaja), Cornelia, Arendina Jacomina, Anthony (a Painter and Assistant Director of the Stedelijk museum “de Lakenhal” in Leiden; he died 19th of February 1939), Cornelia, Arendina Jacomina (she was married to Henri Gerard Winkelman; Commander-in-Chief land and naval forces; He was General from 1st November 1939 and at the time of the German invasion in 1940) and Johannes.