The deuterocanonical books and biblical apocrypha reveal the cultural clash between Jews and Greeks, and between Judaizers and Hellenizers. Both Greeks and Romans valued the foreskin positively, and when they took part in athletic sports or trained in the gymnasium, they did it in the nude. They insisted that the glans had to remain covered, as they strongly disapproved of the custom of circumcision, which was regarded as a cruel and barbaric genital mutilation. The Books of the Maccabees reveal that many Jewish men chose to undergo epispasm, the ancient practice of foreskin restoration by stretching the residual skin, so that they could conform to Greek culture and take part in these sports (); some also left their sons uncircumcised (). This relatively peaceful period came to an end when Antiochus IV Epiphanes attacked first Egypt and then sacked and looted Jerusalem (). Epiphanes determined to force everyone to live the Greek way and abandon the Jewish way. Among other things, he banned circumcision.