Klaas Fortuin, born circa 1842, baker.

Klaas was married to
Froukje Magré, born circa 1849.

• 1 : Geertje Fortuin, born in Harlingen on August 14, 1875.
  

• 2 : Arendina Willemina Fortuin, born in Harlingen on June 8, 1882, died before April 17, 1884, aged at most 1 year.
  

• 3 : Arendiena Wilhelmina Fortuin, born in Harlingen on April 17, 1884, died there on April 21, 1941, aged 57 years.
  Arendiena was married in Harlingen on March 30, 1911, at the age of 26 to Jan van Wier (aged 24 years), born in Harlingen on August 24, 1886, son of Jan Jans van Wier (waggoner's man, waggoner and warehouseman) and Johanna Tigchelaar, cigar maker and baker, died in Noord Bergum on August 23, 1965, aged 78 years.
  Jan was married afterwards in Harlingen on September 29, 1941, at the age of 55 to N.N..
  

• 4 : Jacob Fortuin, born in Harlingen on December 11, 1889.
  

• 5 : Aaltje Fortuin, born in Harlingen on January 30, 1891.