As the recovery of the rich history of the expansive Byzantine Commonwealth pushes forward, we must renew our emphasis on the sturdy multi- and cross-cultural foundation upon which it was constructed. Christian Caucasia was a charter member of the Byzantine Commonwealth, but its social fabric and cultural orientation remained locked on the Iranian world for centuries to come. The fundamentally Iranic, or Persianate, nature of Christian Caucasian society is a reminder of the intense cross-cultural connections of Rome-Byzantium and Iran across late antiquity and into the medieval period.

The Mongols embarked on an explorative incursion in the Caucasus in 1220 before fully invading the area in 1235–1236. Due to their organized and well-thought-out campaign, in a few years they managed to subdue the region from present-day Armenia to Ossetia. From the beginning of their rule, the Mongols relied upon an indirect administrative model, without replacing the pre-existing institutions of the area. The formation of the Ilkhanate in the 1250s moved the focal point of power southward and the political conduct of Caucasia became more indirect and relied on the local aristocracy. The decline of the Ilkhanate in the 1330s opened a process of political readaptation whose more immediate result was the fragmentation of power and the disappearance of a hegemonic center. This chapter discusses the phases of the Mongol conquest, as well as the huge consequences it had for Caucasia.