Which Roman emperors encouraged the spread of Christianity?

By the beginning of the reign of Emperor Constantine, it is estimated that Christianity had around ten percent of the population of the Roman Empire. Constantine gave the Christian Church state patronage, but did not make it the state religion. He gave the Christians the right to distribute state food supplies to the poor, enabling them to proselytise to the recipients. Moreover, during his reign it became politically and socially desirable for some of the more prosperous citizens to be associated with Christianity. Christianity finally became the state religion of the Roman Empire under Emperor Theodosius I, at the end of the fourth century.