Israël Knorringa came from a family of butchers in Uithuizen, in the province of Groningen. He was seen as the ‘black sheep’ of the family. He opened a butcher shop in Assen, but it went bankrupt. In 1907 he moved to Amsterdam with his wife and three children. After a string of failed businesses, he became a shomer (inspector of ritual slaughter) for the Jewish community. His family was very devou…