The second half of the 18th Century saw a new dynasty take hold in Iran. The new Qajar dynasty was founded on slaughter and plunder of Iranians, particularly Zoroasterian Iranians. The Qajars, under their dynasty founder, Agha Mohammad Khan plundered and slaughtered the aristocrats of the previous Zand Dynasty. Following this, Agha Mohammad Khan was determined to regain all lost territories following the death of Nadir Shah. First on his was the Caucasus, and most notably Georgia. Iran had intermittently ruled most of the Caucasus since 1555, since the early days of the Safavid Dynasty, but while Iran was in chaos and tumult, many of their subjects had declared themselves quasi-independent, or in the case of the Georgians, had plotted an alliance with the Russian Empire by the Treaty of Georgievsk. Agha Mohammad Khan, furious at his Georgian subjects, starting his expedition with 60,000 cavalry under his command, defeated the Russian garrisons stationed there and drove them back out of the entire Caucasus in several important battles, and completely sacked Tblisi, and carried of some 15,000 captives back to Iran. Following the capture of Georgia, Agha Mohammad Khan was murdered by two of his servants who feared they would be executed. The rise of the Qajars was very closely timed with Catherine the Great's order to invade Iran once again. During the Persian Expedition of 1796, Russian troops crossed the Aras River and invaded parts of Azarbaijan and Gilan, while they also moved to Lankaran with the aim of occupying Rasht again. His nephew and successor, Fath Ali Shah, after several successful campaigns of his own against the Afshars, with the help of Minister of War Mirza Assadolah Khan and Minister Amir Kabir created a new strong army, based on the latest European models, for the newly chosen Crown-Prince Abbas Mirza.