Martin Luther, a German monk and theologian, is credited with sparking the Protestant Reformation through his Ninety-Five Theses in 1517.

The sale of indulgences, a practice that allowed individuals to purchase forgiveness for sins, became a major point of contention and sparked Luther's criticism.

Luther's three central ideas, known as the Three Solas, emphasized faith alone, scripture alone, and grace alone as the pillars of Christian salvation.

Luther's Ninety-Five Theses, published in 1517, challenged the authority of the Pope and criticized the sale of indulgences.

In 1525, the Electorate of Saxony, a German state, became the first to officially adopt Lutheranism as its religion.

John Calvin, a French theologian, is known for his emphasis on God's sovereignty and the doctrine of predestination, which became central to Calvinism.

Calvin established a theocratic government in Geneva, Switzerland, where he implemented his religious principles and reforms.

Henry VIII, King of England, broke away from the Catholic Church in the 1530s and established the Church of England, becoming its Supreme Head.

The Thirty-Nine Articles, adopted in 1571, outlined the doctrinal beliefs of the Church of England and became a defining document of Anglicanism.

Ulrich Zwingli, a Swiss Reformer, advocated for individual interpretation of scripture and rejected infant baptism, becoming a prominent figure in the early Reformation.

The Peace of Augsburg, signed in 1555, ended the Schmalkaldic War and established the principle of cuius regio, eius religio (whose region, his religion) in the Holy Roman Empire.

Puritanism, a religious movement within Protestantism, emerged in England during the 16th century, emphasizing personal religious experience and individual piety.

The Pilgrims, a group of English Separatists, established the Plymouth Colony in North America in 1620, seeking religious freedom and autonomy.

Celibacy of the clergy was not a major principle of the Protestant Reformation, as many Protestant reformers argued against the requirement of celibacy for priests and monks.

The Council of Trent, held from 1545 to 1563, was a Catholic Council convened in response to the Protestant Reformation, reaffirming traditional Catholic doctrines and practices.