The French revolt and Empire
In 1789, growing discontent with France's feudal government suddenly exploded into an open revolt which drew the attention of all the nations of Europe. The ensuing violence and international involvement triggered more than two decades of nearly continuous warfare as various competing empires sought to reimpose their own views of balanced power. So many related military campaigns were fought over such large areas by so many different factions, that this era has wryly been called the first true world war.
The era itself can be split into two periods; The French Revolution, and the Napoleonic Empire. The Revolution and ensuing republic saw the toppling of the old French monarchy and its replacement by a series of sporadically violent civilian administrations. At the peak of the violent period, known as "The Terror," the former king and queen were cruelly put to death. This act galvanized the other nations of Europe against France, and guaranteed that no matter what improvements might be made later, the resulting nation would never enjoy the cooperation of Europe's other leaders.
The events which followed were typical in the history of revolutions; an army general seized control of the government. This general however, named Napoleon Bonaparte, was of unusual intelligence and charisma, and he had seized control of what today would be called a superpower. The presence of this charismatic military genius as the head of France vastly complicated Europe's political landscape and broadened the atmosphere of confrontation which was destined to continue until one of the two sides was defeated. Napoleon himself was not of a disposition to resist playing the same power games as those around him, and so not until 1815 did the wars end with the battle of Waterloo and the return of a monarch to Paris.