His flexible, compassionate guidelines for Christian community forever shaped monastic life—and influenced Western society.

The massive treatise set forth a theological system so influential it has been declared eternally valid.

They were ordained ministers and missionaries. Then their hearts were "strangely warmed," and their changed lives gave rise to a worldwide movement.

If Jesus was truly God, how could he be truly human as well? Leo the Great helped guide a critical council to a clear answer.

Hated by Protestants and Catholics alike, these "radical reformers" wanted to not merely reform the church but restore it.

This Latin translation stood as the preeminent Bible text for centuries—and set the standard for future translators.

Was the wayward Luther free to dissent? A German council rendered a judgment.

In an epochal council, the Catholic Church undertook its most searching self-examination ever and renewed itself for a modern world.

Waves of pilgrims and soldiers embarked for the Holy Land, beginning an era of exploration, conquest, defeat, and folly.

An obscure monk invited debate on a pressing church issue—and touched off a history-shattering reform movement.

A Baptist preacher had a dream that guided one of the most profound social movements of our times.

Long-standing differences between Western and Eastern Christians finally caused a definitive break, and Roman Catholics and Eastern Orthodox still remain separate.

Responding to the Reformation, the council charted the Catholic church's course for the next 400 years.

A brief listing of significant dates that also earn a place in the "Christian History 100"

Either adored or abhorred, the reformer and his teachings live on in his monumental work.

Using his revolutionary invention—printing from movable type—he made the Scriptures potentially accessible to every person.

How to help new adherents adhere—here.