The Holy Roman Empire, also known as The First Reich or The Holy Roman Empire of the German Nation after 1512, was a polity in Central and Western Europe, usually headed by the Holy Roman emperor. It developed in the Early Middle Ages and lasted for almost one thousand years until its dissolution in 1806 during the Napoleonic Wars.
On 25 December 800, Pope Leo III crowned Frankish king Charlemagne as Roman emperor, reviving the title in Western Europe more than three centuries after the fall of the ancient Western Roman Empire in 476. The title lapsed in 924, but was revived in 962 when Otto I was crowned emperor by Pope John XII, fashioning himself as Charlemagne's and the Carolingian Empire's successor, and beginning a continuous existence of the empire for over eight centuries.
From 962 until the twelfth century, the empire was the most powerful monarchy in Europe. The functioning of government depended on the harmonious cooperation between emperor and vassals; this harmony was disturbed during the Salian period. The empire reached the apex of territorial expansion and power under the House of Hohenstaufen in the mid-thirteenth century, but overextension led to a partial collapse.
While the office of emperor had been reestablished, the exact term for his realm as the "Holy Roman Empire" was not used until the 13th century. A process of Imperial Reform in the late fifteenth and early sixteenth centuries transformed the empire, creating a set of institutions which endured until its final demise in the nineteenth century. On 6 August 1806, Emperor Francis II dissolved the empire following the creation – the month before, by French emperor Napoleon Bonaparte – of the Confederation of the Rhine, a confederation of German client states loyal not to the Holy Roman emperor but to France.
