We just learned about the Pentarchy of people ruling the church.
Another part of early Christianity is the Hagia Sophia.
This is a very big church that was built in the city of Constantinople in the year 532.
For almost a thousand years it was the biggest church in the world.
It is now a museum in the city that is now called Istanbul.
(from: wikipedia - hagia sophia)
Kid Facts - Blast from the past: Apostolic Age