French government between 1789 and 1799 followed the sweep of a pendulum, going from absolutism in 1789 to constitutional monarchy in 1790, on to radical republicanism in 1792-1794 (with the Terror as the most dreadful aspect), then back to a middle position with the Directory of 1795-1799, and finally on to the right with Napoleon, "first consul" in 1799 and emperor in 1804. - Britannia.com
When Napoleon abolished the Consulate by declaring himself emperor in 1804, it could be viewed to be the most dramatic system of government in France between 1789 to 1812.
By 1812, whatever ambiguities had existed about Napoleon's imperial ambitions, gave way in a wave of further annexations, including most of northern Italy, all territories of the west of the Rhine, and substantial parts of the Low Countries.
At its zenith, France commanded a European empire that stretched from the Atlantic to Poland and from the Baltic to the Mediterranean.
Behind France's expanding domain was the most formidable military in Europe, more than 600,000 strong in 1812, and a vast economic sphere of control organized around the Continental System.
It was also in Napoleon's time that the people saw the beginning of the French collapse. Russia and Sweden signed treaties with Britain. As Russia pursued Napoleon's armies across Europe, Prussia and eventually Austria joined the anti-Napoleonic coalition, and in 1813 and early 1814, they, along with Russia, fought bloody campaign against the French. (see more here: After Victory: Institutions, Strategic Restraint, and the Rebuilding of Order after Major Wars).