Description of the coat of arms: split by red and silver, in front and behind each three five-petalled roses in mixed colours with green sepals and golden slugs.

It remains uncertain which area is to be designated by the name of the dominion of Aldenburg. The only certainty is that it cannot mean the county of Altenburg (Kr. Altenburg). Petrus Albinus - and probably Horm in his wake - refers it to Merseburg, where the name Altenburg has stuck to the oldest fortifications, a Carolingian castle. Around 910, Altenburg was for the most part in the hands of a lord Erwin, whose daughter Hatheburg married King Henry I. The castle was thus inherited by the lord. Heinrich single-mindedly developed the property he inherited into a rich estate complex, which can still be traced in the royal list of table estates in the 12th century.

It is also not entirely improbable that it was equated with Altenberga (district of Jena). In Zedler's universal encyclopaedia it is listed as "Altenberge or Aldenberg, ancient dominion in Thuringia, not far from Jena" and is expressly described as a former Altenburg fief. It was the ancestral seat of a branch of the Burgraves of Orlamünde, who had appeared among the vassals of the Counts of Orlamünde since 1266. After the Count's War, i.e. after 1345, they became fief holders of the Wettins, to whom the last Burgrave sold the dominion of Altenberga in 1393.

Even a clue that at first seems promising, to solve the problem with the help of heraldry, does not help in the end. It is striking that the coat of arms of the Aldenburg dominion is identical with that of the old Coburg mintmaster family, the Lords of Rosenau. Apart from the Coburg area, they were also richly endowed in Thuringia around Gotha*. Nowhere, however, is there a relationship to a lordship of Aldenburg or similar name. (Since the Rosenau were of lower noble origin, they could not have been the owners anyway). Whether the rose in the coat of arms of the county of Altenburg and its feudal sovereignty over the lordship of Altenberga could be used to construct a conclusive connection would require more detailed investigation.