Pazin was first mentioned as Castrum Pisinium in a 983 deed regarding a donation by Emperor Otto II to the Diocese of Pore?. It then belonged to the Imperial March of Istria, which had originally had been under the suzerainty of the newly established Duchy of Carinthia in 976, but separated together with the March of Carniola in 1040.
In the 12th century Mitterburg Castle was in possession of the Lower Carniolan count Meinhard of Schwarzenburg, who held the office of a Vogt of the Pore? bishops (in Latin documents he is known as Cernogradus), and established the Pazin County (earldom). Upon his death, Pazin was inherited by his son-in-law Count Engelbert III of Gorizia (G�rz) in 1186.
While most of Istria had gradually been annexed by Venice, Engelbert's descendant Count Albert III of Gorizia in 1374 bequested his Mitterburg estates to the Austrian House of Habsburg, who attached them to their Duchy of Carniola and gave it out in fief to various families, the last of which was the comital House of Montecuccoli from 1766
