The term Kaiserpfalz is a 19th-century appellation that overlooks the fact that a king of Germany did not bear the title of the Holy Roman Emperor (granted by the Pope) until after his imperial coronation which required expeditions to Italy (Italienzug), which mostly were only undertaken years after his accession to the throne and in many cases not at all.
Like their peers in France and England, the medieval emperors of the Holy Roman Empire did not rule from a capital city, but had to maintain personal contact with their vassals on the ground.
The Merovingians in the Frankish Empire already ruled according to the feudal principle in which a ruler does not rule over a territory with specific land boundaries with the support of administrative officials, as in a territorial state, but rather his sovereignty was based on a personal relationship of dependence between feudal lords and their vassals (Personenverbandsstaat, a "personal dependency state").
The emperors continued to travel to their elections and coronations at Frankfurt and Aachen, to the Imperial Diets (which developed from the “Hoftage”) at different places and to other occasions such as weddings, negotiations with other monarchs or military campaigns.
Moreover, they were not always grand palaces in the accepted sense: some were small manor houses or fortified hunting lodges, such as Bodfeld in the Harz.
Unlike a pfalz, where the itinerant ruler stayed for a while and enacted his sovereign duties, a royal estate (Königshof) was just a farm with a smaller manor owned by the kingdom, which was occasionally used by the kings as a transit station.
At a minimum, a pfalz consisted of a palas with its Great Hall or Aula Regia, an imperial chapel (Pfalzkapelle) and an estate (Gutshof).
[5] In the complex's Palatine Chapel, today the rotunda of Aachen Cathedral, more than 30 Roman-German kings, who saw themselves as the direct successors to Charlemagne, were crowned over a period of 600 years in front of the gold shrine with his relics.
In the Hohenstaufen era of the Roman-German kingdom, important imperial princes began to demonstrate their claims to power by building their own pfalzen.
Important examples of these include Henry the Lion's Dankwarderode Castle in Brunswick and the Wartburg above Eisenach in Thuringia, built by the Thuringian count Louis the Springer.
They oppressed less powerful nobles, fought the urban rulers (patricians and guilds), illegally seized imperial fiefdoms, introduced customs duties, new taxes and even royal regalia.
The ruling patricians of these cities not only entertained the kings generously, but - like the Augsburg merchant and banker Jakob Fugger - financed their wars with huge loans.