This paper is a study of the military history of Qajar Iran’s confrontation with Russia in two 19th century wars. The study examines Iran’s response to Russian attempts at annexation of the Caucasus in three distinct phases. First, Qajar Iran’s reliance on its tradition army, namely relying on highly mobile tribal cavalry, light artillery, and poorly fortified fixed positions such as forts and towns. Second, the beginning of developing a European style army (nezam-e jaded), first with the help of Russian and Polish POWs and fugitives, later with the aid of the French. This phase included fortifications of towns (especially Irvan) based on European engineering, and building of modern, European style forts (e.g Abbas Abad), as well as the training of an infantry and artillery force for the army. Third, was the expansion of the Nezam forces under British trainers and its development into a military force capable of facing the regular Russian army in an effective manner. The paper will explain Qajar Iran’s military strategy and examines a number of battles to illustrate how military tactics evolved. The main conclusion of the paper is that while the Qajar state managed to improve its military performance against Russian aggression, it ultimately failed to understand the strength and strategic superiority of the Russian Empire and resources available to it. The study is based on original Persian, English and French sources. Sources include both histories and memoirs and observations by Iranian and non-Iranian observers.