Complex sentence: Alexander II's assassination in 1881 rendered his position precarious, however, and after Konstantin Pobedonostsev, intent on reversing the liberal innovations of the previous reign, emerged as the most powerful policy-maker, Milyutin resigned his office.
Split into simpler sentences: Alexander II's assassination in 1881 rendered his position precarious, however. After Konstantin Pobedonostsev, intent on reversing the liberal innovations of the previous reign, emerged as the most powerful policy-maker, Milyutin resigned his office.