By the end of the 1st century AD, bans against castration had been enacted by the emperors Domitian and Nerva in the face of a burgeoning trade in eunuch slaves. Sometime between 128 and 132 AD, Hadrian seems to have temporarily banned circumcision, on pain of death. Antoninus Pius exempted Jews from the ban, as well as Egyptian priests, and Origen says that in his time only Jews were permitted to practice circumcision. Legislation under Constantine, the first Christian emperor, freed any slave who was subjected to circumcision; in 339 AD, circumcising a slave became punishable by death.