Barend Coster was a son of Jacob Coster and Sara Gompel. He was born on 15 January 1883 in Rotterdam, where he married Betje van Coevorden on 13 September 1905, born on 6 December 1884 as daughter of Levie Israël van Coeverden and Mietje Heimans. The couple had four children, viz. Sara in 1906, Hendeline in 1908, Jacob in 1912 and in 1918 Mietje was born. Barend Coster earned his living as a shopkeeper in hats and caps.
One of their children, Hendeline Coster and her husband survived the Shoah. She married Levij Salomonson on 9 August 1933 in Rotterdam. They left for Eindhoven on 9 September 1938, where they lived at Anna van Englandstraat 23. They moved one more time to the Voorterweg 170 and were registered on 23 July 1946 at Nicolaas Beetsstraat in Eindhoven. On 26 August 1946 the marriage in Rotterdam was dissolved by divorce. The two other children, Jacob and Mietje, were killed during the Shoah, together with their families.
After they got married, the Barend Coster couple lived at Warmoezierstraat 27 in Rotterdam, after which five more moves followed, before the family ended up in Noordmolenstraat 7a and 8b. This was followed by a final move to Vlaggemanstraat 26b on 7 February 1936.
When their daughter Sara had married her first cousin Daniël de Vries on 1 August 1928, the newlyweds De Vries moved in with Barend and Betje Coster in the Noordmolenstraat. And when the Coster family moved to the Vlaggemanstraat in 1936, Sara and Daniël de Vries also went with them with their firstborn son Meijer.
During the large-scale raids at the beginning of October 1942, Barend Coster and his wife Betje van Coevorden were arrested and taken to Westerbork, where they were brought in between 3 and 5 October 1942. At the same time, that fate also befell Daniël de Vries with his wife Sara Coster and their two children Meijer and Bernard.
Barend Coster and his wife Betje van Coevorden were finally deported to Auschwitz on 2 November 1942 and immediately murdered in the gas chambers of Auschwitz-Birkenau on arrival there on 5 November 1942.
Sources include the City Archive of Rotterdam, family registration cards of Barend Coster and Daniël de Vries; the file cabinet of the Jewish Council, registration cards of Betje Coster-van Coevorden and the wikipedia website jodentransporten vanuit Nederland.nl.