Klaas Jakobus Knol, born in Kolderveen, christened on May 21, 1789, son of Jacobus Knol (house-husband) and Jantje Jans Wind, peat cutting supervisor.

Klaas was married (1) to
Hendrikje Willems Meinderts, born circa 1749 (?), died in Terband on September 5, 1821, aged approximately 72 years.

Klaas was married in Aengwirden on March 1, 1823, at the age of 33 (2) to
Hilligje Jakobs van der Klok (aged 25 years), born in Rotsterhaule on January 18, 1798, christened there on February 18, 1798.

• 1 : Jacob Klazes Knol, born in Terband on July 9, 1825, veenwerker and bargeman, died in Harlingen on August 3, 1902, aged 77 years.
  Jacob was married in Aengwirden on April 13, 1851, at the age of 25 to Sjoukje Roelofs Visser (aged 22 years), born in Benedenknijpe on June 23, 1828, daughter of Roel Bonnes Visser (houtwerker) and Antje Oebeles Platje, died in Benedenknijpe before September 26, 1895, aged at most 67 years.