After the Great Schism of Christianity in 1054 (which divided Christianity between a Catholic Church in the west and an Orthodox Church in the east) the Byzantine city of Constantinople was the center of Eastern Orthodoxy. However, after the fall of Constantinople in 1453, the center of Orthodox Christianity moved to Moscow. The Russian title for ‘king’ - Tsar - comes from the Russian belief that Moscow is the ‘Third Rome’ which carries on the legacy of the Roman Empire.

The Kongolese Kingdom was founded in the fourteenth century and existed, as either an independent state or as a Portuguese vassal-state, until the early twentieth century. After the arrival of Portuguese missionaries the Kongolese Kingdom converted to Christianity in the sixteenth century.

Martin Luther’s initial concerns with the Catholic Church were primarily related to abuses of the clergy. Luther abhorred the practices of simony, nepotism, and usury and decried the sale of indulgences. Simony is the practice of selling one’s position within the church; usury is the practice of extending loans for the purposes of making money (something forbidden by Christian doctrine); nepotism is the practice of granting titles and positions on the basis of favor rather than merit; the sale of indulgences refers to the church’s practice of literally selling salvation to wealthy patrons who were willing to pay to guarantee their entrance into heaven.

The Protestant Reformation began in the sixteenth century and spread most quickly and effectively in Northern Europe - Germany, the Netherlands, the British isles. It threatened to remove the influence of Catholicism from Europe, but never really took effect in Southern Europe. The Catholic Church enacted the Counter Reformation at the Council of Trent (1545-1563) and fought back against the forces of Protestantism. The Protestant Reformation had a massive impact on European, and subsequently American, society.

Contrary to popular belief, Martin Luther did not argue against the Real Presence of Christ in the Eucharist, a stance that would later put him at odds with other Reformation leaders. His main argument in the 95 Theses is actually salvation through faith alone, not through indulgences, good works, or any other Church intervention. Luther also believed that priests should be appointed based on their qualifications, not their family connections, and he wanted services to be conducted in local vernaculars so all could understand.

Ishmael I of the Safavid Dynasty conquered Tabriz and established the Twelver school of Shi'a Islam as the official religion of the empire.

The Protestant Reformation began in 1517 when the reformer Martin Luther nailed his 95 Theses to the door of a church in Wittenberg. Luther was concerned with abuses of the clergy, namely the sale of indulgences; the practice of simony; and nepotism. Originally Luther intended to reform the church and contribute to a discussion within the framework of church authority, but eventually his movement evolved into a widespread reformation.

The Aztec religion included elements of human sacrifice. The Aztecs waged many brutal wars of conquest in Central America before the arrival of the Europeans. The people they conquered would be assimilated into the empire and some of their citizens would be sacrificed to appease the Aztec gods.

Henry VIII was a devoted Catholic king before his break from Rome, even earning the title "Defender of the Faith" after he published literature attacking Martin Luther. However, his desire to end his marriage to Katherine of Aragon overcame his love of the Church, and the English Reformation began as an attempt to circumvent Church laws and legitimize Henry's new marriage to Anne Boleyn. Henry would later argue that his decision was based on English laws that had long been ignored, although Parliament did not officially make Henry the head of the English church until the schism was already well under way. Henry's argument that the Church had no authority in England had already been used to get rid of his Lord Chancellor, Cardinal Wolsey, who had failed to secure Henry's divorce and was branded as a traitor.

John Calvin founded the Calvinist denomination in the 1530s, preaching that God had chosen a small group of people to be saved and planned on damning everyone else. God's decision was immutable, hence the term "predestination." While Calvinists did live a highly strict lifestyle and were required to adhere to Calvinist teachings, these actions had no bearing on their admittance to heaven. Like most Protestant denominations, they also did not believe in purgatory.