In the history of Azerbaijan, the Early Middle Ages lasted from the 3rd to the 11th century. This period in the territories of today's Azerbaijan Republic began with the incorporation of these territories into the Sasanian Persian Empire in the 3rd century AD. Feudalism took shape in Azerbaijan in the Early Middle Ages. The territories of Caucasian Albania became an arena of wars between the Byzantine Empire and the Sassanid Empire. After the Sassanid Empire was felled by the Arab Caliphate, Albania also weakened and was overthrown in 705 AD by the Abbasid Caliphate under the name of Arran. As the control of the Arab Caliphate over the Caucasus region weakened, independent states began to emerge in the territory of Azerbaijan.[1][2][3][4][5][6]