1 8 0 4 - 1 8 1 3 ), ▁the ▁first ▁of ▁a ▁number ▁of ▁Rus so - Pers ian ▁wars ▁during ▁the ▁ 1 9 th ▁century , ▁and ▁the ▁most ▁dev ast ating ▁and ▁hum ili ating ▁one . ▁By ▁the ▁end ▁of ▁the ▁war ▁in ▁ 1 8 1 3 ▁and ▁the ▁resulting ▁Tre aty ▁of ▁Gul istan , ▁Q aj ar ▁Iran ▁was ▁forced ▁to ▁c ede ▁Georgia , ▁most ▁of ▁the ▁modern - day ▁Republic ▁of ▁A zer ba ij an , ▁and ▁D ag est an ▁to ▁Russia . ▁The ▁only ▁C au cas ian ▁territ ories ▁remaining ▁in ▁Iran ian ▁hands ▁were ▁what ▁is ▁now ▁Armen ia , ▁the ▁N akh iche van ▁Khan ate ▁and ▁the ▁Tal y sh ▁Khan ate . ▁The ▁next ▁war , ▁the ▁Rus so - Pers ian ▁War ▁( 1 8 2 6 - 1 8 2 8 ), ▁resulted ▁in ▁an ▁even ▁more ▁hum ili ating ▁defeat , ▁with ▁Iran ▁being ▁forced ▁to ▁c ede ▁remaining ▁C au cas ian ▁regions , ▁as ▁well ▁as ▁having ▁Russian ▁troops ▁tempor arily ▁occup ying ▁Tab riz ▁and ▁Iran ian ▁A zer ba ij an . ▁As ▁Iran ▁was ▁unw illing ▁to ▁allow ▁the ▁Rus si ans ▁to ▁gain ▁possession ▁over ▁its ▁C au cas ian ▁territ ories ▁in ▁the ▁North ▁C au cas us ▁and ▁South ▁C au cas us , ▁the ▁mill enn ia ▁old ▁ancient ▁t ies ▁between ▁Iran ▁and ▁the ▁C au cas us ▁region ▁were ▁only