Domitian (ruled 83-95 AD) was the son of emperor Vespasian (ruled 68-79 AD). He declared himself a god and was best known for his proclamation that he be worshiped by all. The Christian persecution began under Nero but it got to a whole new level under Domitian. He ordered that all Christians who did not worship him be sent to Patmos, a Greek prison island. Among the believers sent there was the Apostle John who saw the visions and wrote the book of Revelation while on Patmos.
By AD 95, many senators in Rome were becoming fed up with Domitian's "divinity" and his policies. Thus in AD 96, Domitian was murdered and the Christians enjoyed a brief period of peace from persecution under Nerva (ruled 95-102 AD)