Jacob Lopes Dias was the son of Abraham Lopes Dias and Sara Montezinos. He was first married to Sara Haring. The couple had five children: Anna, Abraham, Jacques David, Catharina and one child that survived the war.
Sara Lopes Dias-Haring died at the end of Juli 1940. In May 1941 Jacob Lopes Dias married Elisabeth Aandagt.
Amsterdam Municipal Archives; record card of Jacob Lopes Dias