Apostolic Era and Constantine

• After Jesus Christ's death, the Apostles spread his religion. The Apostolic Era transitions to the rise of Constantine around 320 AD. He was the first Roman ruler to accept the Christian faith. Constantine gathered a council of Christian leaders at Nicea in 325 AD in order to standardize accepted beliefs for the emerging Church.
  
  

Schism of 1054

• By the 11th century, two centers of Christian spiritual-political power existed--Rome and Constantinople. Disagreements led to the split into "western" Christianity led by Roman Catholicism, and Byzantine, or "eastern" Christianity.
  
  

Indulgences and Reformation

• Martin Luther protested the Catholic Church because it was preoccupied with the sale of indulgences. Indulgences forgave political punishments for sins, especially if the sinner acted with good intent. Martin Luther's "95 theses" were a series of claims challenging certain Catholic doctrines. Protestant Christianity was the eventual result of the Reformation.