By 1700 when Philip of France was named by Charles II of Spain as his successor, Europe had fallen into a delicate balance of power. Austria, Prussia, France, Spain, and England were all independent nations that were powerful enough to balance each other out so that no one nation could conquer the others. However, if France and Spain were now one royal family, combined, their armies could take on the might of any of these nations and win, thus causing the balance of power to swing in the favor of France.

The French Revolution officially ended when Napoleon crowned himself Emperor of France in 1804. This put an end to 15 years of chaos in France at the hands of a revolving door of leadership. The French Government had gone through the hands of dozens of men, most of whom were run out of the country or killed by rivals seeking to fill the power vacuum left by the French Monarchy.

1804-1814 is considered the apogee of Napoleon's political power and authority as Emperor of France. He would be unchallenged as French ruler until after his abdication and exile to Elba in 1814-1815. Both Robespierre and Louis XVI were executed long before 1804. Finally, neither anarchy or a foreign army would rule France entirely, and never at all for more than a year.

During the Renaissance, Italy consisted of five main city-states: Venice, Milan, Florence, the Papal States, and the Kingdom of Naples, each with its own system of government. There were struggles for power among these various political entities, and their internal and external struggles made Italy vulnerable to invasion.  Continental powers (notably the French and Austrians under Charles V) fought for territorial control in Italy in the late fifteenth and sixteenth centuries. 

In the wake of the Protestant reformation, some German princes embraced Lutheranism for myriad reasons, which increased political division within the German states of the Holy Roman Empire. Charles V and the French Valois dynasty went to war repeatedly throughout the sixteenth century, and much of the fighting took place in Germany. The French kings tended to support Lutheran princes to promote disunity and defy Charles V. Eventually, Charles V accepted the Peace of Augsburg, which recognized Lutheranism and permitted German princes to choose whether their states would be Catholic or Lutheran.

The Peace of Westphalia marked the end of the Thirty Years' War in 1648.  In Germany, it reinforced the previous stipulations of the Peace of Augsuburg, with the addition that Calvinism was also permissible. The northern German states were largely Protestant; the southern German states were Catholic.

Neville Chamberlain was Prime Minister of the United Kingdom from 1937 to 1940. He tried to maintain peace for his people, as the British were still weary from World War I. The strategy of appeasement had been used on Hitler since 1935, but the most notable measure of it was granting the Sudetenland, part of Czechoslovakia which had a large German population, to Germany, which Chamberlain agreed to in 1938. Hitler then conquered the rest of Czechoslovakia, which outraged Britain and France, but there was little else they could do at that point. When Hitler threatened to invade Poland, he was warned that it would mean war, and upon his invasion in 1939, Britain and France declared war on Germany. 

The Thirty Years' War erupted when the Peace of Augsburg (1555) no longer seemed to be sufficient to keep the peace in the various German states; the growth of Calvinism, which was not accounted for in the previous treaty, further threatened the status quo. Lutheran princes formed a Protestant Union (1608), and Catholic princes formed the Catholic League (1609). Tensions came to a head in 1618, when Protestants in Bohemia threw the representatives of a Catholic king out of a window (the Defenestration of Prague). The war lasted for thirty years, with both the Austrian and Spanish Hapsburgs siding with the Catholic princes.

The Edict of Nantes was issued in 1598 by the French King Henry IV. It brought to an end the French Wars of Religion, which had raged violently for almost forty years. The Edict extended religious tolerance to Calvinists (known as Huguenots) within the Kingdom of France, although they were still persecuted on both a state and local level on a frequent basis. The Edict was revoked in 1685 by King Louis XIV, who issued the Edict of Fontainebleau. The Edict of Nantes can also be understood as an extension of the Edict of St. Germain, which was issued by Catherine de Medici during the period of time when she reigned as regent of the French Kingdom. The Edict of St. Germain allowed for French Calvinists to worship privately, but was widely ignored and came at the height of tensions between the Catholic and Protestant populations, tensions that would very soon break out into civil war through the French Wars of Religion.

The Peace of Utrecht ended the War of Spanish Succession (1701-1714). The War of Spanish Succession broke out when King Charles II, the last Hapsburg monarch of Spain, died childless and without a clear legitimate heir to the throne. It was Charles’ wish that the throne, and the entire Spanish colonial inheritance, be left to Philip, Duke of Anjou, who just so happened to be the grandson of the French King Louis XIV. During this time period, the Kingdom of France was growing dramatically in power and influence, and the idea of a Kingdom of France and Spain, with all their overseas holdings, all under the dominion of King Louis XIV, troubled the other ruling princes of Europe, who were worried that France would become a hegemonic power and upset the balance of power in Europe. The Peace of Utrecht allowed Philip to inherit the Spanish throne on the condition that he renounce any future claims to being King of France.