Barend van Velzen was a son of Levie van Velzen and Naatje Wurms. He married on 10 January 1917 in Amsterdam to Rebecca Viskoper a daughter of Benjamin Viskoper and Anna van Bever. The couple had four children: Louis and the here mentioned Salomon and Raphael. Their son Benjamin survived the Holocaust, but not his daughter-in-law and Benjamin's wife Adèle Keyser.
The family has resided in Antwerp …