When Johannes Hendricus Hensing was born on 1 October 1843, in Leiden, Holland, Netherlands, his father, Hendricus Hensing, was 30 and his mother, Elisabeth Helena van Maastricht, was 26. He married Helena Johanna Houps on 12 June 1867, in Leiden, Holland, Netherlands. They were the parents of at least 6 sons and 3 daughters. He died on 24 June 1927, in Leiden, South Holland, Netherlands, at the age of 83, and was buried in Leiden, South Holland, Netherlands.