The Church's influence and power grew significantly during the 4th Century, particularly after the Edict of Milan in 313 AD, which granted religious freedom to Christians in the Roman Empire.

Constantine the Great issued the Edict of Milan in 313 AD, which legalized Christianity and granted religious freedom to Christians in the Roman Empire.

Constantine the Great was the first Christian emperor of the Roman Empire, reigning from 306 to 337 AD.

The Council of Nicaea was convened in 325 AD to address the Arian controversy and establish the Nicene Creed, which defined the orthodox Christian doctrine regarding the nature of Jesus Christ.

Ambrose of Milan was the influential bishop of Milan who played a significant role in the conversion of Constantine the Great to Christianity.

The Tome of Leo was a document issued by Pope Leo I in 449 AD that defined the primacy of the Bishop of Rome.

The Benedictine Order was founded by Benedict of Nursia in the 6th Century.

Catharism was a movement that emphasized the importance of personal religious experience and criticized the wealth and power of the Church.

Pope Urban II launched the First Crusade in 1095.

The Knights Templar was a military order founded in the 12th Century to protect pilgrims traveling to the Holy Land.

Pope Julius II initiated the construction of the new St. Peter's Basilica in the 16th Century.

Protestantism was a movement that emphasized the importance of individual conscience and the right to interpret the Bible without the mediation of the Church.

Martin Luther is known for his Ninety-Five Theses, which criticized the sale of indulgences and sparked the Protestant Reformation.

The Council of Trent was convened in response to the Protestant Reformation to address doctrinal and disciplinary issues.

Pope Paul III initiated the Counter-Reformation, a movement aimed at responding to the challenges posed by the Protestant Reformation.