Despite being created in the mid-12th century, the Holy Roman Empire would go on to be one of the longest-lasting political units in European history. One of the main reasons for this endurance was its decentralization, as the empire was composed of many smaller duchies and fiefdoms, making it easier to rule. 

In 1152, Frederick Barbarossa became King of Germany. He wanted to fight back against decentralization and sought to restore imperial authority over not only Germany but also Lombardy in Northern Italy. Ruling from 1155-1190, he was the first Holy Roman Emperor and imagined the glory of the old Roman Empire. This attempt at centralization by Barbarossa did not sit well with the papacy, due to the fact that Lombardy was inside their sphere of influence in Italy. If it was taken over, the Pope would lose much of the Catholic Church’s power and influence over other secular rulers. Because of this, the Lombards and the Papal States allied, with Frederick responding by burning the city of Milan in Northern Italy. Ultimately, Frederick was defeated by the combined Papal and Lombard force, and was forced to make up with the Pope and recognize Lombardy as a sovereign nation.  After Barbarossa’s death in 1190, there were two candidates for Holy Roman Empire elected by two different families: the Hohenstaufens and Welfs. The Welf candidate, Otto, promised to obey the church while the Hohenstaufen candidate and Barbarossa’s son, Frederick II looked like he was going to follow in his father’s footsteps. In 1209, Otto became Emperor but surprisingly went back on his promises to the Pope when he invaded Southern Italy. In response to this, Pope Innocent II supported Frederick II who essentially became de facto Emperor after Otto’s position crumbled. Despite the support from Innocent II, Frederick II eventually became a larger foe than his father  after Sicily was fully conquered with all of their Church properties plundered. While he was victorious in Sicily, Frederick II focused so much attention on Italy that his imperial power in Germany was compromised. Frederick II was later excommunicated and intended to march on Lyon and imprison the Pope, but died in 1250. After the reigns of Frederick Barbarossa and Frederick II, it was much too late to centralize the Holy Roman Empire as the German princes became too powerful. Germany would continue to be highly decentralized until the establishment of the German Empire in the 19th century.