Pope John Paul II turns an ancient institution into the modern papacy we know today.

Wartime popes navigate their place as a spiritual leader in an increasingly political world.

The power of the papacy is questioned, splintering what was once a universal church.

As the pope's temporal power and political influence grows, so does corruption in the church.

The challenge of balancing spiritual and worldly interests changes as papal authority grows.

Go back 2,000 years to see how the papacy and Catholicism spread throughout Europe.