The Holy Roman Empire was a union of territories in Central Europe during the Middle Ages and the Early Modern period under the authority of the Holy Roman Emperor. Although the first Holy Roman Emperor was considered to be Charlemagne, crowned on 25 December 800, the continuous line of emperors began only with Otto the Great in 962. The last was Francis II, who abdicated and dissolved the Empire in 1806 during the Napoleonic Wars. It was officially known as the Holy Roman Empire of the German Nation from the late 15th century onwards.

The Empire's territorial extent varied over its history, but at its peak it encompassed the territories of present-day Germany, Austria, Switzerland, Liechtenstein, Luxembourg, the Czech Republic, Slovenia, Belgium, and the Netherlands as well as large parts of modern Poland, France and Italy. For much of its history the Empire consisted of hundreds of smaller kingdoms, principalities, duchies, counties, Free Imperial Cities, and other domains. Despite its name, the Holy Roman Empire never included Rome within its borders.