Pieter de Jong, born in Harlingen on November 1, 1872.

Pieter was married to
Thecla van Oosterbaan, born in Harlingen on December 28, 1878.

• 1 : Thomas de Jong, born in Harlingen on November 17, 1898.
  Thomas was married to Antje Vellinga, born in Franeker on March 9, 1903.
  

• 2 : Frans de Jong, born in Harlingen on September 17, 1900.
  

• 3 : Trijntje de Jong, born in Harlingen on October 15, 1903, housekeeper, died in Oosterbierum on April 17, 1978, aged 74 years.
  Trijntje was married in Harlingen on January 17, 1924, at the age of 20 to (and divorced in Harlingen on August 18, 1936 from) Klaas Tigchelaar (aged 25 years), born in Harlingen on March 16, 1898, son of Tjerk Tigchelaar (municipal cleaner) and Neeltje de Bruin, barber and retail dealernational lotery, died in Harlingen on September 20, 1981, aged 83 years.
  Klaas was married afterwards in Harlingen on October 12, 1936, at the age of 38 to Antonia van 't Veld (aged 33 years), born in Maarssen on July 22, 1903, daughter of Wilhelmus van 't Veld and Sjoerdje Bakker, died in Harlingen on March 12, 1975, aged 71 years.