The Holy Roman Empire (800-1806) was a loose confederation of hundreds of territories.

It spanned modern-day Germany, Austria, Czech Republic, Switzerland, parts of Italy & France.......and more.
The central location of Nuremberg is marked.
Over its lifetime, between 50-60 emperors ruled these lands (47 of them being German) and it is considered to be the First Reich (which, significantly, lasted over 1,000 years).
For many centuries Nuremberg was considered the 'unofficial capital' and the Imperial Regalia had been kept in the city since 1424.

A painting of the regalia being brought to the church of the Holy Spirit
Nuremberg has a magnicient imperial castle standing high above the city.

Every newly-crowned Emperor was required to hold his first 'Imperial Diet' (Reichstage) in Nuremberg.
The 'diets' were the administrative side of the Empire and the supreme lawmaking authority making Nuremberg a hub for governance and imperial prestige.

A Diet of the Holy Roman Empire held in Nuremberg.
In 1796, the advancing French army threatened Nuremberg and the regalia were moved to Vienna.
However, in 1938, as soon as Hitler annexed Austria, the regalia were returned to Nuremberg.

SS troops guard the newly returned Imperial Regalia.
With its history, Hitler described Nuremberg as the "most German of all German cities" and an ideal spiritual home for his rallies.
Note: After WW2, the US returned the Imperial Regalia to Vienna.