ysz al án c ▁( S lan ec ), ▁January ▁ 1 0 , ▁ 1 8 5 7 ), ▁by ▁whom ▁she ▁had ▁three ▁sons , ▁all ▁of ▁whom ▁died ▁un mar ried ▁and ▁without ▁any ▁issue . ▁Rec ent ▁investig ations ▁taken ▁by ▁one ▁of ▁his ▁great - grand d augh ters ▁and ▁an ▁English ▁gene alog ist ▁pract ically ▁confirm ▁this ▁late ▁ancest ry , ▁not ▁explaining , ▁however , ▁the ▁mot ives ▁why ▁he ▁didn ' t ▁use ▁his ▁father ' s ▁name ▁but ▁El ston , ▁his ▁English ▁n anny ' s ▁surname . ▁ ▁Career ▁ ▁Felix ▁El ston ▁was ▁prominent ▁during ▁the ▁Sie ge ▁of ▁Se v ast opol ▁and ▁was ▁promoted ▁to ▁Colonel ▁in ▁ 1 8 5 5 . ▁After ▁his ▁marriage ▁in ▁ 1 8 5 3 ▁with ▁the ▁He ir ess ▁of ▁Count s ▁Sum ar ok ov , ▁he ▁received ▁the ▁title ▁of ▁Count ▁Sum ar ok ov - El ston . ▁By ▁Imperial ▁Dec ree ▁of ▁September ▁ 8 , ▁ 1 8 5 9 ▁he ▁was ▁author ized ▁to ▁use ▁the ▁her edit ary ▁title ▁of ▁his ▁father - in - law , ▁with ▁the ▁condition ▁of ▁using ▁his ▁surname . ▁From ▁ 2 3 ▁August ▁ 1 8 6 3 ▁to ▁ 3 ▁February ▁ 1 8 6 9 ▁he ▁was ▁an ▁At aman ▁of ▁Kub an ▁C oss acks ▁and ▁from ▁ 1 8 6 5 ▁he ▁was ▁a ▁governor ▁of ▁Kub an . ▁ ▁During ▁his