Joseph Aandagt was a son of Isaac Aandagt and Aaltje Kool. Because his parents were divorced in 1934, Joseph Aandagt stayed in the Bergstichting since 1937.
Joseph had five other siblings: Jacob, Elias, Rebecca, Elisabeth and Asser. Beside them he had two half-sisters 541892 en 568686.
City Archive of Amsterdam, archive card of Joseph Aandagt and Isaac Aandagt.