This chapter investigates the archaeological landscapes of the frontiers of the Sasanian Empire. Drawing on evidence from current and archived archaeological surveys, in combination with high-resolution remote sensing datasets such as CORONA spy photography, we compare the organisation of settlements and defensive structures of the Sasanian frontier zones in response to a variety of external pressures. These varied from the Roman Empire in the west to less centralised entities, including nomadic groups, in the southwest and north-east. Following a general discussion of the multiple manifestations of Sasanian frontiers drawn from southern Mesopotamia (Iraq), northern Syria and north-eastern Iran, the main focus of the chapter is on the complex frontier landscape of the southern Caucasus, particularly the area of modern Azerbaijan, Georgia and Daghestan. We discuss the role of linear barriers, including the Gorgan Wall in north-eastern Iran and the Ghilghilchay and Derbent Walls in the Caucasus, irrigation systems, and alignments of fortifications and settlements in shaping their local landscapes. By placing the archaeological remains of the Sasanian Empire in a wider context we are able to examine the relationships between military installations, settlement patterns, infrastructure and geographical features such as mountain ranges and rivers. Comparing the different case studies allows us to conclude with some general statements on the nature of Sasanian power in the frontier territories of the empire.

As a large territorial entity, the Sasanian Empire encompassed a variety of geographical, environmental and socio-cultural zones. Even within the northern and western reaches discussed here, the empire included the high mountain ranges of the Taurus, Caucasus and eastern Anatolia, the fertile dry farming plains of much of northern Mesopotamia and Gorgan, heavily irrigated southern Mesopotamia and steppe and desert regions in various guises (Fig. 5.1). Threats to Sasanian power were similarly diverse, from the agrarian might of the Roman Empire in the west to smaller local ‘states’, client kingdoms and decentralised nomadic groups in the north and north-east. This diversity had a profound impact on the organisation and character of the frontier regions at the edges of imperial control. In this chapter we make use of data acquired as part of the recent upsurge in interest in Sasanian frontiers across the study region,1 as well as satellite imagery and textual information, to examine the structure and function of the frontier zones in different areas.