Johannes Baukes Feenstra, born in Workum on September 19, 1863, son of Bauke Johannes Feenstra (sailor) and Sybrigje Pieters Katsma, shop assistant and officer Salvation Army.

Johannes was married in Leeuwarden on May 19, 1897, at the age of 33 to
Jantje de Bock (aged 22 years), born in Haulerwijk on June 8, 1874, daughter of Egbertus Bernardus Jacobus de Bock and Lucia Theodora Pierik.