Calvinism was the most effective Protestant faith at penetrating Polish society, and it was the dominant religion in the country for several decades at the height of the Protestant Reformation; however, the Catholic Counter-Reformation was wildly successful, and Calvinism survived only in limited numbers.

The Battle of Mohacs was fought between the forces of Hungary and the Ottoman Empire in 1526. It ended in an overwhelming victory for the forces of the Ottoman Empire, which led the people of Hungary to abandon their Catholic faith, because they thought that it no longer offered the protection of God's grace. They took up Protestantism in large numbers and would hold the faith for a century or so until the Catholic Counter-Reformation returned Hungary to Catholicism.

In the two centuries before the Protestant Reformation began (in 1517), there were still numerous reform movements going on around Europe. One of the most influential and widely known is the Hussite movement initially inspired by Jan Hus and Jerome of Prague. They were both Czech-speaking people living in the region of Central-Eastern Europe called Bohemia. Their reform was centered around rectifying abuses within the church, and their discourse and correspondence is rife with references to the Pope as the "Antichrist." Not surprisingly, given the atmosphere of this time period, they were also both executed for heresy in the early fifteenth century. It is believed that their writings and martyrdom laid the foundations for the swift rise of Protestantism in Bohemia and Poland.

The Lutheran movement was spread initially through the German-speaking princely states of central Europe and was primarily a German-speaking movement throughout. The German-speaking people of Hungary were influenced by the writings of Luther and his German compatriots more than anyone else, and the religion of Lutheranism took off far more swiftly with them. The Lutheran Confession was adopted in Hungary in 1545. The Magyar people of Hungary (people who speak Hungarian) favored the Reformed Church of Switzerland, of Zwinglianism, and they adopted the Helvetic Confession in 1567. A Confession, to help clarify, is an expression of faith or a definition of what the group believes.

By the beginning of the seventeenth-century Protestantism had taken a tenuous hold of the populations of Poland, Lithuania, and Hungary. The Catholic Counter Reformation started winning back the hearts and minds of the people—primarily by motivating the nobles to withhold funds from Protestant missionaries and by coercing those who still resisted. The Jesuit organization was extremely active in this work. The Jesuits were formed right before the Counter-Reformation began and were extremely active throughout the next few hundred years in "purifying" the church while attempting to eradicate the gains of the Protestant Reformation. They were particularly successful in Eastern Europe, where the majority of each country was reverted back to Catholicism.

The Treaty of Tordesillas was drawn up in 1492 between the Spanish and the Portuguese and signed by the Pope. It basically divided up the whole world, but especially the American hemisphere, into spheres of Spanish and Portuguese influence in an attempt to prevent future conflict.

John Cabot was an Italian explorer who sailed for North America under the sponsorship of King Henry VII of England in 1497. He is credited as being the first European to set foot on the mainland of the North American continent, although most historians believe that the Vikings had previously done so in the eleventh century. 

Although all of these countries would be significant throughout the period of European exploration and colonialism, it was the Portuguese who had the most early success. Portugal established colonies on the Atlantic coast of Brazil, and was the first to travel around Africa, the first to reach India, and the first to reach the Far East.

The Seven Years' War, often called the French and Indian War, was fought between France and Britain between 1756 and 1763. Due to the global nature of the two countries' empires, the war was fought around the world and resulted in numerous territories being exchanged between the two world powers. In the treaty that ended the war, Britain gained control of French holdings in North America and also in the Indian subcontinent.

The six major players in the age of European exploration were France, Britain, the Netherlands, Spain, Portugal, and Sweden. Germany, which was not a unified country until the 1870s, was not a major player in the age of exploration.