Markus Sanders was a son of Joseph Sanders and Jeannette van Dam. He married in Rotterdam on 21 August 1918 to Johanna Gerardina Pijnappels from Rotterdam, age 22, daughter of Josephus Wilhelmus Jacobus Pijnappels and Petronella Beijer. He divorced her on 24 October 1924 and remarried on 27 April 1927 in Rotterdam to Joanna Heijlen from Antwerp, 34 years of age, daughter of Carolus Heijlen and Ma…