When Hendrik Valk was born on 12 April 1845, in Maassluis, South Holland, Netherlands, his father, Hermanus van der Valk, was 39 and his mother, Aagje Griffijn, was 31. He married Neeltje Noordam on 11 June 1870, in Naaldwijk, South Holland, Netherlands. They were the parents of at least 3 sons and 3 daughters. He died on 2 March 1889, in his hometown, at the age of 43.