Around 330 AD, at the same time the Roman Empire was expanding, the ancient Kingdom of Axum (present-day Ethiopia) declared Christianity to be its official religion. According to legend, the Ethiopian government official who was converted in Acts 8 was an important early figure in the church there (30s AD).
In what is now the Coptic Orthodox Church, the Archbishop of Alexandria ended up in charge of it. It is Orthodox, much like the other ancient churches that did not acknowledge the primacy of the Bishop of Rome.
According to how they responded to the Bishop of Rome, often known as the Pope, ancient churches may be roughly classified into three categories (though the Bishop of Alexandria also uses that title). Some, commonly referred to as Orthodox, never acknowledged his authority over the entire church and hence rejected Rome's effort to amend the Nicene Creed.
Roman Catholics are those who still acknowledge his authority over the entire church.
Some first acknowledged his authority but then had second thoughts and disregarded it. They are the Protestant Magisterials (Anglicans, Lutherans in Germany and Scandinavia, Presbyterians in Scotland).