

For naming conventions, see Medieval Kingdoms of Western Europe.
The Holy Roman Empire was a realm that existed for about a millennium in Central Europe, ruled by a Holy Roman Emperor. Its character changed during the Middle Ages and the Early Modern period, when the power of the emperor gradually weakened in favour of the princes. In its last centuries, its character became quite close to a union of territories. Note that even though the name states it as a "Roman" empire, the Holy Roman Empire was populated primarily by Germans.