The flag of the Holy Roman Empire is a yellow background with a black double headed eagle in the center.
History of the flag[]
The earliest Imperial Banner of the Holy Roman Emperor (14th century)
Imperial Banner of the Holy Roman Emperor (early 1400s)
.png "Banner of the Holy Roman Emperor with haloes (1400-1806).png (694 KB)")
Imperial Banner of the Holy Roman Emperor (1430-1806)
Imperial Banner of Frederick III (1437-1493)
Imperial Banner of Maximilian I and Charles V (1493-1556)
Imperial Banner of Charles V (1519-1556)
References[]
https://en.wikipedia.org/wiki/Flags_of_the_Holy_Roman_Empire