Coenraad van der Sluis was the son of Wolf van der Sluis and Esther Sak. He travelled around peddling his wares. In 1880 in Den Bosch he got married to Saartje Eijsman, the daughter of Hartog Eijsman and Ester Kloots. The couple had six children, of whom Hartog and Maurits died at a young age. Another child, Wolf, died in the war.
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