The Holy Roman Empire (Latin: Sacrum Imperium Romanum, German: Heiliges Römisches Reich, Dutch: Heilige Roomse Rijk, Italian: Sacro Romano Impero, Czech: Svatá říše římská, Slovene: Sveto rimsko cesarstvo, French: Saint-Empire romain germanique) was a vast conglomerate of states across Central Europe which was proclaimed at the imperial coronation of Otto I in 962. It lasted for almost a millennium, until its dissolution by Emperor Francis II in August 1806, following the defeat of Habsburg Austria by Napoleon Bonaparte. The empire was known simply as the ‘Roman Empire’ until the reign of Frederick I Barbarossa (r. 1155 – 1190), who called it ‘Holy’ to signify his self-proclaimed authority over the Papacy. A 1512 decree of the Imperial Diet formally declared ‘Holy Roman Empire of the German Nation’ to be the official name.
The Holy Roman Empire had no official national flag but rather an imperial banner associated with the person of the Holy Roman Emperor. From around 1430, the banner’s basic design was a gold field with a black double-headed eagle in the centre, sometimes adorned with haloes and the escutcheon of the reigning Emperor.