sentences:  It was then located in the former Slavic principality of Carantania, which had become a Frankish march by the end of the 8th century.Arnulf of Carinthia, the Carolingian king of East Francia and Holy Roman Emperor, grew up here and used the castle as a "Kaiserpfalz" residence.Part of the Duchy of Carinthia from 976, the Moosburg estate was later held by the noble House of Gorizia ("Görz") which finally lost their remaining Carinthian possessions to the Habsburg emperor Frederick III about 1460.