The exact territorial extent of Merania is unknown. It probably included the town of
Fiume (Rijeka) and the coast of the
Kvarner Gulf, either on the
Istrian peninsula or across from it. The author of the
Historia de expeditione Friderici imperatoris, an account of
Barbarossa's crusade of 1190, writing around 1200, refers to "the Duke of Dalmatia, also called Croatia or Merania", specifying (imprecisely) that the duchy neighboured
Zahumlje and
Raška. The actual duchy contained at most only a small part of the region of
Dalmatia, which had historically belonged to
Croatia. By the twelfth century,
Croatia was in a personal union with Hungary. This territory came under imperial control during the reign of
Henry IV. According to the fourteenth-century
Chronicon pictum Vindobonense (Viennese Illustrated Chronicle), the "march of Dalmatia" (
marchia Dalmacie) was occupied by the
Carinthians between 1064 and 1068 during the reign of
Dmitar Zvonimir, who in fact was not king of Croatia until 1075. Despite this inconsistency in the chronicle, several modern historians, led by Ljudmil Hauptmann, have connected this Dalmatian borderland with the later duchy of Merania. According to the historians Miho Barada and Lujo Margetić, it was the accession of the young King
Stephen II of Hungary in 1116 that provided an opportunity for the Emperor
Henry V to annex the entire eastern coast of Istria and the coast opposite as far as the river
Rječina, including the city of Fiume. This territory, conquered for the emperor by the lords of
Duino (Devin), became known as Merania. It is not clear to what extent the Meranian dukes of the Dachau or Andechs lines ever managed to exert their control over the region. There are other theories proposing a different etymology of "Merania". Erwin Herrmann argues that the name cannot have actually been in use as the name of a region, since it is unknown save as the name of the duchy that existed between 1152 and 1248. He argues that it is probably formed from the name of the seat of the lordship, which he identifies with the town of
Marano Lagunare. The region he identifies as that between the rivers
Tagliamento and
Corno. In older literature, Merania is sometimes mistakenly identified with
Meran, a town in the
Tyrol, because the Andechser dukes held land in the Tyrol.
August Dimitz, while correcting the Tyrolean error, equates Merania with the
march of Istria. ==House of Dachau (1152–1180)==