1461:

Second Battle of Saint Albans

In the long-running Wars of the Roses, a previous battle had taken place at Saint Albans nearly six years earlier, a very brief incident that gave Richard, Duke of York, the upper hand in the conflict. But soon the opposition rose once more and war broke out again in 1459.

The Duke had been dead some time when Henry's indomitable Queen Margaret and York's son Edward both sought to capture London. It was Richard Neville, Earl of Warwick (also known as the Kingmaker), who met the queen at Saint Albans, but he lost the battle, leaving his prisoner, King Henry VI, to Margaret's forces.

Margaret made a grave error when she allowed her forces to pillage the town and Abbey of Saint Albans. The people of London, hearing of this behavior, sent her a message saying she would not be welcome unless she could guarantee that her troops would not so mistreat Londoners. While Margaret thought this over, Edward York and Richard Neville entered London, where York soon was crowned King Edward IV.

1537:

Appendix on the Papacy signed

In June of 1536, Pope Paul III had issued a bull calling for a general council to deal with the Reformation. The Schmalkaldic League, a group of leading Protestant reformers, gathered in Schmalkalden to consider a response. Although Martin Luther had written something for the occasion, the league decided against endorsing it, and instead assigned Philip Melancthon to the task of writing a work addressing the primacy of the pope.

Melancthon's treatise declared that the papacy's claim of supremity over church and secular kingdoms alike was false and, after addressing what the Protestants considered abuses in the papal office, recommended the office be disposed of. Upon reading the treatise to the League it was signed as a confession of faith. The treatise was published anonymously in 1540.

1600:

Giordano Bruno

Astronomer, mathematician, and philosopher, Bruno set forth several advanced scientific theories, including those of the infinite universe and multiple worlds. He even went beyond the Copernican theory, which centered a finite universe of fixed stars around the sun (although Bruno's grasp of astronomy and physics was not exactly complete). After a successful if rather controversial career in the sciences, he was arrested and tried by first the Venetian and then the Roman Inquisition, who demanded he retract all his theories. Bruno refused, and by the order of Pope Clement VIII he was declared an impenitent heretic and burned alive.