Harmen Geerts Knol, born circa 1859.

Harmen was married to
Soukje Heins van der Vliet, born circa 1873 (?).

• 1 : Frans Knol, born in Oldeboorn on March 30, 1896.
  Frans was married in Idaarderadeel on October 18, 1919, at the age of 23 to Hiltje Feenstra (aged 23 years), born in Grouw on December 10, 1895, daughter of Frederik Feenstra and Antje Venema, died in Weststellingwerf on February 5, 1975, aged 79 years.