This paper deals with issues concerning the historical background that engendered the imperial (titular) Duchy of Merania and the modality by which this mysterious territory became part of the Holy Roman Empire. The author fi rst demonstrates that Meran(ia) refers to a microregion situated between the Učka mountain range and the river Rječina at the very east of the Istrian peninsula that historically belonged to the Kingdom of Croatia and Dalmatia. Second, he outlines interpretations regarding how this patch of land became part of the Holy Roman Empire. The takeover of Merania is posited in the second half of the 1070s, in the period of Croatian king Zvonimir who fostered enmity with the Holy Roman emperor Henry IV by offi cially taking the side of the reform papacy and pope Gregory VII during the Investiture Controversy. It is in this context that the attacks against Zvonimir’s kingdom ensued, led by a noble knight Wezelin whose identity is discussed in detail; this marks the beginning of the imperial takeover of Merania.