From the longer Wikipedia page [1]
The Holy Roman Empire (Latin: Sacrum Imperium Romanum; German: Heiliges Römisches Reich), occasionally but unofficially referred to as the Holy Roman Empire of the German Nation, was a multi-ethnic complex of territories in Western and Central Europe that developed during the Early Middle Ages and continued until its dissolution in 1806 during the Napoleonic Wars. The largest territory of the empire after 962 was the Kingdom of Germany, though it also included the neighboring Kingdom of Bohemia and Kingdom of Italy, plus numerous other territories, and soon after the Kingdom of Burgundy was added. However, while by the 15th century the Empire was still in theory composed of three major blocks – Italy, Germany, and Burgundy – in practice, the links between these blocks had become so unsubstantial that only the Kingdom of Germany remained, nearly all the Italian territories for instance having become in effect part of a narrowly-defined Habsburg dynastic patrimony, unconnected to the Empire. The external borders of the Empire did not change noticeably from the Peace of Westphalia – which acknowledged the exclusion of Switzerland and the Northern Netherlands, and the French protectorate over Alsace – to the dissolution of the Empire. By then, it largely contained only German-speaking territories, plus the Kingdom of Bohemia. At the conclusion of the Napoleonic Wars in 1815, most of the Holy Roman Empire was included in the German Confederation.