Watze Feenstra, born in Leeuwarden on January 11, 1883, son of Jacobus Feenstra (baker's man and sigarenwinkelier) and Tietje de Vries.

Watze was married in Leeuwarden on February 26, 1908, at the age of 25 to
Sjoukje Hemminga (aged 23 years), born in Leeuwarden on August 9, 1884, daughter of Sjouke Hemminga and Grietje Ablij.