Jonas Knoop, born 31 May 1877 in Amsterdam, was a son of Hartog Barend Knoop and Benvenida Cohen de Solla. He married at the age of 31 on 4 February 1909 in Amsterdam his 27-year old niece Marie Knoop, who was born 10 August 1881 in Amsterdam as daughter of his father’s brother Salomon Knoop, who was married to Ribca Lopes Cardozo.
The Knoop-Knoop couple had eight children, namely Salomon in 1910,…