Jonas Velleman, 'Joop', was born in Haarlem on 12 July 1925, the son of Hartog Velleman and Betje Schaap. His brother Louis was more than six years older. The family also lived in Utrecht and Rotterdam and then returned to Haarlem. Jonas went to the technical school.
When deportation threatened, Louis arranged hiding places for his parents and himself. Jonas said he had an address too, but in fact he slept at the homes of different acquaintances. In 1942 he was arrested in Amsterdam. He was held in the prison on Weteringschans, in Scheveningen and in the Amersfoort camp. Early in 1943 he was taken to the Vught camp. On 22 February 1943 he wrote a letter from there in which he asked for food parcels. He died in Vught on 25 February 1943, aged 17. His death certificate gives pneumonia as the cause. His parents and his brother survived the war.