Who was the Roman emperor who first allowed freedom of worship?

Answer 1

No Roman emperor first allowed freedom of worship. The Romans allowed the conquered peoples to observe their religions and to follow their customs and respected thises. Without such a policy, the Romans would not have been able to control a huge empire with many religions and ethnicities.

With regard to Christianity, it was never made illegal or banned. There were alternations between periods of toleration and periods of persecution. Only two persecutions were actually documented and were severe. Other claims that there were persecutions are not documented and if they did occur, they were mild. The mentioned persecutions were the Decian persecution (250-260) and the Great Persecution (303-311).

The first emperor who ended a persecution was Gellienuswho ended the Decian persecution by issuing an Edict of Toleration in 260.

The Great Persecution was ended by the Edict of Toleration by (emperor) Galerius in 311. Co-emperors Constantine the Great and Licinius issued the Edict of Milan in 313 which reiterated the toleration of Christianity, declared the toleration of all religions and provided for compensation by the state for people who had bought or received as a gift Christian property which had been confiscated during the persecution to the Christians. This edict was aimed at the governor of Syria who continued the persecution, disregarding Galerius' edict.