Belnart van der Sluis was a son of Elias van der Sluis and Sara Frank. He was born on 27 October 1890 in Vlijmen in North Brabant and he was a traveler in bakery products. On 14 December 1922, he married Serlina Salomons in Amsterdam, a daughter of Meijer Salomons and Bloeme de Paauw, who was born on 20 September 1889 at Rapenburgerstraat 165 in Amsterdam.
On 9 September 1901, the van der Sluis family moved to 's-Hertogenbosch with father Elias, mother Sara and the children Anna, Esther, Aaron, Rosa, Izaak and Belnart, after which Belnart stayed in Zwolle for a few more months in 1909, but otherwise lived in Den Bosch until his marriage.
Serlina Salomons moved from Amsterdam to Hilversum with her parents, brothers and sisters Machiel, Philip, Simon, Samuel Esther, Abraham and herself on 28 May 1897. On 7 January 1918, Serlina was registered again in Amsterdam, where she started working as a masseuse before getting married.
After the marriage was concluded in December 1922, Belnart and Serlina moved into a house on the 1st floor at Muiderstraat 9 on 15 December 1922, where their daughter Bloeme was born on 10 March 1924. And on 15 April 1931, the Van der Sluis family moved to Hunzestraat 11, 1st floor. The last address of the Van der Sluis family was Louis Bothastraat 23, 2nd floor, where they were forced to move on 11 December 1942.
Belnart van der Sluis, together with his wife Serlina Salomons, was arrested on 20 June 1943, during the major raid secretly prepared by the Germans, and deported to Westerbork. There they ended up in different barracks, Belnart in barracks 72 and Serlina in barracks 71. On 29 June, both were deported to Sobibor in a transport of almost 2400 victims, where they were immediately murdered in the gas chamber upon arrival there on 2 July 1943.
Sources include the Amsterdam City Archives, family registration cards of Meijer Salomons (1863) and Belnart van der Sluis; archive cards of Belnart van der Sluis, Serlina Salomons and Bloeme van der Sluis; Amsterdam residence cards regarding Salomons and Van der Sluis/Ruyschstraat 13, Hunzestraat 11 and Louis Bothastraat 23; the file cabinet of the Jewish Council, registration cards of Belnart van der Sluis and Serlina van der Sluis-Salomons and the website Jodentransporten uit Nederland.nl/29 June 1943..