This work is an attempt to study the turbulent and dark period of late 18th century Persia. We begin with the death in 1193 A.H./1179 A.D. of the Vakil, Karim Khan Zand, after nearly twenty years of rule. Immediately thereafter the conflicts and contradictions inherent in a semi-feudal monarchy came to the surface, giving rise to the most violent and chaotic anarchy. The Vakil's own tribe, the Zands, failed to grasp their only chance of survival which was to remain unified against their rivals. Instead, one after another Zand prince usurped supreme power and killed his own kinsmen. In this process the country was destroyed and eventually witnessed the final downfall of the Zands in 1209/1794. From the death of the Vakil, the Zand 's most formidable rival, .Ag.a Mohammad Khan Qajar, was consolidating his power in the northern provinces of the kingdom. By careful planning and patience, he contributed to the weakening and eventual tqtal annihilation of ·the Zand dynasty. In this thesis we also attempt to clarify the underlying currents behind these events. The dynamics of the society and social and economic forces are studied in detail. This period of history is of particular importance as it marks the end of a semi-feudal regime based on tribal military support. Before the advent of the 19th century, which witnessed the sedentarization of nomadic tribes and the formation of a regular and disciplined army under the Qaj ars. In this study of an important, but little known, period of transition, particular emphasis is laid on socio-economic aspects such as trade, religious life and the structure of late 18th century Persian society.