1509-11

Raphael (Raffaello Sanzio) completed "School for Athens" fresco in the Apostolic Palace of the Vatican. Set in classical times, the masterwork emphasizes reason, dialogue, and the liberal arts—a marked departure from Michelangelo's nearby Sistine Chapel, painted around the same time (1508-12)

1517

Martin Luther (1483-1546), an ordained priest of the Roman Catholic Church, posted his 95 Theses on the door of the castle church in Wittenberg, Germany. Luther first opposed the dispensation of indulgences by the church, and eventually expanded his thinking to include broad reforms of the church. He was excommunicated in 1521.

1527

Under Charles V (1500-1558; Holy Roman Emperor 1519-1558), Rome was sacked by rebellious troops and Pope Clement VII was imprisoned.

1535

John Calvin (1509-1564) began his reformation work in Geneva, and in 1536 published Institutes of Christian Religion, a systematic description of Protestant thought.

1543

Nicholas Copernicus (1473-1543) published De revolutionibus orbium coelestium, his theory of planetary motion.

1545

Council of Trent opened by Pope Paul III for church reform in light of the Protestant Reformation.