For anything to become "official," it has to be codified by statute, or at least by general agreement of a group.
Many religions that are considered "official" got that way via political or social organizations that formed within the religion. Others came about due to conversions of existing rulers. Often they are exported to other areas by force of arms. Conquerors, who often use the excuse of pillaging in the name of some god, tend to being their religions with them.
In Western Europe some religious groups achieved political control from within (or, in the case of King Henry the 8th, changed affiliations).
No, atheism was not the official religion of Cold War Russia. The Soviet Union was officially atheist and promoted atheism as the state ideology, but it did not establish atheism as a religion. Religion was actively suppressed during this time, and believers faced persecution.
Baptist
The religion of Ancient Rome was polytheistic in origin, in line with religious traditions in wider Iron Age Europe. From an early time, however, the Roman Republic was strongly influenced by Hellenistic Greece, and much of the recorded religion of pre-Christian Rome is a syncretism of indigenous with Hellenistic religion.
In the 1600s, the predominant religion in Britain was Christianity. Specifically, the Church of England was the established church, but there were also Catholics, Puritans, and other Protestant sects practiced in different parts of the country.
Styx as a band does not specifically adhere to a particular religion. Members of the band may have individual religious beliefs, but the band as a whole does not have an official religious affiliation.
AD 300s
Christianity was adopted as the official religion of the empire in 380 AD.Christianity was adopted as the official religion of the empire in 380 AD.Christianity was adopted as the official religion of the empire in 380 AD.Christianity was adopted as the official religion of the empire in 380 AD.Christianity was adopted as the official religion of the empire in 380 AD.Christianity was adopted as the official religion of the empire in 380 AD.Christianity was adopted as the official religion of the empire in 380 AD.Christianity was adopted as the official religion of the empire in 380 AD.Christianity was adopted as the official religion of the empire in 380 AD.
391 AD by Theodosius I.
on Feburary 27th, 380 they made Nicene Christianity the official Christian religion of Rome, however it is unclear whether this was intended to apply to pagans.
Theodosius I was the emperor who made Christianity the official religion of the Roman empire.Theodosius I was the emperor who made Christianity the official religion of the Roman empire.Theodosius I was the emperor who made Christianity the official religion of the Roman empire.Theodosius I was the emperor who made Christianity the official religion of the Roman empire.Theodosius I was the emperor who made Christianity the official religion of the Roman empire.Theodosius I was the emperor who made Christianity the official religion of the Roman empire.Theodosius I was the emperor who made Christianity the official religion of the Roman empire.Theodosius I was the emperor who made Christianity the official religion of the Roman empire.Theodosius I was the emperor who made Christianity the official religion of the Roman empire.
Islam was the official religion of Saudi Arabia ever since its constitution in the 1920s (as a result of the unification war between Nejd and Hejaz). Prior to this it was the official religion of the Kingdom of Nejd from as early as records exist on the existence of an independent Nejd.
There is no 'official' religion in the USA
Islam is the official religion in Afghanistan.
Theres no official religion in Tanzania. The government do not have religion, the citizen do have.
I believe a shared belief can be officially classified as a religion once it has at least 50 official followers. Like Jedi.
There is no official religion anywhere in the United States.
There is no Official religion in Puerto Rico.