The Thirty Years' War began as a conflict between Catholic and Protestant forces in Central Europe and the Holy Roman Empire, but as the war wore on it evolved into a continuation of the centuries long battle for continental supremacy between the Bourbons of France and the Hapsburgs of the Holy Roman Empire. The Thirty Years' War is often broken down into four distinct phases—The Bohemian Phase, the Danish Phase, the Swedish Phase, and the French Phase.

Gustavus Adolphus was the commander of the Swedish forces during the Thirty Years' War. Sweden fought on the side of Protestantism and the anti-Hapsburg side.

Gustavus Adolphus was the commander of the Swedish forces throughout the Thirty Years' War. Victory of his army at the Battle of Brietenfield prevented the Hapsburg forces from reunifying the German-speaking world under the Catholic faith. 

The Protestant Church of England was founded in the sixteenth century by Henry VIII after his divorce from Catherine of Aragon and subsequent marriage to Anne Boleyn.

During the Protestant Reformation, France was still a primarily Catholic kingdom ruled by a Catholic king, but the number of French Protestants (called Huguenots) was growing rapidly. In an attempt to encourage secular unity, King Henry IV issued the Edict of Nantes in 1598 to establish some religious toleration of Protestants in France.

The Edict of Nantes was issued in 1598 by the French King Henry IV. The purpose of the Edict was to bring to an end the French Wars of Religion and provide religious toleration of Protestants in the French kingdom.

The Ninety-Five Theses was posted in All Saints' Church in Wittenberg, Saxony in the Holy Roman Empire. It is credited for starting the Protestant Reformation.

The Protestant Reformation in England began in earnest in 1535 when King Henry VIII proclaimed himself king and head of the Church of England. The Protestant Reformation in England was motivated less by spiritual concerns and more by the personal desires of Henry and his ministers.

Utopia was written by Thomas More in the early sixteenth century. It tells the story of a perfect society where everyone is equal, although historians have long disagreed on whether it is meant to be taken literally, satirically, or somewhere in between. More was a longtime friend and advisor to Henry VIII; however, when Henry broke from the Catholic Church, More found that his conscience would not let him follow suit. More chose execution over obedience to the Church of England and is considered a martyr of the Catholic faith. 

The Ursulines were a religious order, formed in the early sixteenth century, that was dedicated to providing religious education to young girls. They were particularly prominent in France.