In the first and second centuries, Roman emperors sporadically persecuted Christians because they refused to take part in pagan rituals. Then the emperor Alexander (212-235) placed Jesus among the pagan icons in his pantheon, initiating a period of serenity that ended with his assassination. In 303, the emperor Diocletian started the final, and most grisly, assault on Christians. Their eyes and tongues were cut out; they were burned at the stake; some died in hot metal chairs. The persecution ended when Constantine gained power in 312. After a power struggle with another emperor, Constantine credited his triumph to the Christian God. From then on, the empire courted Christianity, finally naming it the official religion in 380.