Though the first Qajar Iranian ruler, Agha Mohammad Khan, had reconquered the Caucasus and all of Iran in several swift campaigns, such as the harsh re-subjugation of Georgia in 1795, Iran would eventually irrevocably lose all of the Caucasus region to neighbouring Imperial Russia during the course of the 19th century, which had a crucial impact on the region of modern-day Iranian Azerbaijan. Shortly after the reconquest of Georgia, Agha Mohammad Shah was assassinated while preparing a second expedition in 1797 in Shusha. The reassertion of Iranian hegemony over Georgia did not last long; in 1799 the Russians marched into Tbilisi, which would mark the beginning of the end of the Iranian-ruled domains in the Caucasus, comprising modern-day Georgia, Armenia, the Republic of Azerbaijan, and Dagestan thanks to the 19th century Russo-Persian Wars.