Bouk Daniel de Jong, born in The Hague in the year 1881, son of Cornelis de Jong and Gelske Feenstra.

Bouk was married in Voorburg on May 22, 1907, at the age of 26 to
Clasina de Wit (aged 24 years), born in Voorburg on December 13, 1882, daughter of Denys de Wit and Clasina van Dijk.