It is not known when and by whom the castle was built. It was fortified during the reign of
Byzantine Emporer Justinian I (). The castle was taken over by
Great Seljuks in 1054-1055, when Bayburt and its surroundings were captured as one of the first areas conquered and settled by the Turks in
Anatolia, and by the
Saltukids after the
Siege of Manzikert (1054). It remained in the hands of the
Danishmendids for a while. It is understood from the inscriptions that the castle was repaired in this period in the most comprehensive way by the Seljuks. Accordingly, Seljuk sultan
Tughril II () and the ruler of
Erzurum, virtually rebuilt this castle, which was a fortified position against attacks especially from the
Empire of Trebizond. The castle, which remained in the hands of the Akkoyunlular for a while, was transferred to the
Ottomans in 1514. Bayburt Castle underwent a major restoration in 1541 by
Suleiman the Magnificent () when its importance increased during
his Iran campaign. A later repair took place by
Murad III (). A record from 1520 states that there were 397 guards and a large amount of cannons, rifles and war materials in the castle, which was an important fortified place for the protection of Bayburt and this road on the
Trabzon-
Iran transit route for centuries. The castle and its settlement inside the citadel, which were occupied and destroyed from time to time, and after largely destroyed by the Russians during the
Russo-Turkish War (1828–1829), were left to their own devices until the 1980s. Some parts of the castle that were in danger of complete collapse were repaired after this date while the structures inside the citadel were not revived. == Architecture ==