Charlemagne was a Germanic king who is held responsible for the restoration of the Empire in Western Europe. His father was the King of the Franks, Pepin the Short, from whom he would end up inheriting the throne after his father died in 768 and completed it with the eastern territories granted to his brother Carloman, who died in 771 and he left said territory.
His mandate was characterized by being expansive, since he continued with the conquest and annexation of the Lombard kingdom, located in northern Italy, which was carried out in the year 774, through the alliance carried out by the Franks and the papacy. After the domination of Italy. Charlemagne concentrated his energies in Saxony, an undertaking that required eighteen consecutive campaigns that took place between 772 and 804. Charlemagne thus dominated the most important kingdom of the time; But in order for it to remain intact, it had to fight constantly, many times putting out rebellions or resistance within its territories and others to secure the borders against external enemies to the empire.
Among the campaigns against external enemies it is important to mention the war against the Avars on the eastern border, which led him to dominate the territories of present-day Hungary, Croatia and some Serbian regions.
Geographically speaking, the kingdom of Charlemagne represents the totality of what is currently the territory of France, Switzerland, Austria, Holland, Belgium and Luxembourg, and a large part of Germany, Italy, Hungary, the Czech Republic, Croatia and Slovakia. Reason why it is considered a predecessor of the unit in Europe. It is important to note that no monarch until then had managed to gather such a large territory under his command since the fall of the Roman Empire.
In 800, Pope Leo III appointed Charlemagne as emperor, thus initiating a new Germanic Empire, which would have its repercussions until the 19th century. However, the continuity of this Germanic Empire with the Western Roman Empire had already waned some 300 years earlier. The restoration of the imperial idea was practically a fantasy, since it meant an aspiration to a universal power over the rest of the various kingdoms, which would be the temporary counterpart of the supremacy of the pope on the religious plane.