According to Šufflay, Kruja was the town at the centre of the medieval region of Arbanum. The medieval fortress of Kruja was build on a steep hill between the rivers Mat and Išmi. Archaeological excavations have found a 6th to 8th centuries cemetary. Kruja was first mentioned as bishopric see in 879, but it is unclear if the settlement already was fortified. Files of the time of the rule of King Alphonso V of Aragon and Naples suggest that this was a privilege given by Emperor Manuel I Comnenos given in the year 1165. In 1253 Kruja subortinated itself to the Emperor of Nicaea John III Vatatzes but already in 1258 Kruja was conquered by despote Michael II of Epirus and the town became again Byzantine after an Angevin Intermezzo from 1268-1280. Andronikos II Palaiologos granted several privileges to the town and made it the capital of a Byzantine province. 1342 Krja was conquered by Stefan Uroš IV Dušan. After the disintegration of the Serbian empire the local noble family of Thopia ruled over Kruja. After two years under Venetian rule it was ruled by the Ottomans for a short time, before again being independent until 1415 when Kruja was conquered by the Ottomans. Kruja was also the capital of the Skanderbeg rebellion from 1443 onwards. It was three times unsuccessfully besieged by the Ottomans and only fell in 1478 after the death of Skanderbeg (1468). The fortress is quite well preserved, despite an earthquake in 1617 and a part-destruction after an rebellion in the year 1832. Šufflay suggests that Kroja was, like other towns and cities in Illyria and Dalmatia, mainly inhabited by a Romanesque speaking population well into the 12th century. Only after the decay of the Latin population the region became Albanised. Kruja was part of a defensive system for Dhyrrachion/Durres. (AA, I, 48 (10, 11), 57 (14) - David Croensis; SN ZSp. 788 - oppidi Croarum).