Hilarion or Ilarion (Russian: Иларион, Ukrainian: Іларіон, Belarusian: Іларыён) was the first non-Greek Metropolitan of Kiev. While there is not much verifiable information regarding Hilarion's biography, there are several aspects of his life which have come to be generally accepted.
According to the Primary Chronicle Hilarion served as a priest or monk in the princely residence of Berestovo (Berestov) near the Rus' capital of Kiev. He acquired the reputation of well-educated scholar and upon the death of Metropolitan Theopemptus in 1049, Hilarion was proclaimed the metropolitan of Kiev by Yaroslav the Wise, the Grand prince of Kiev, who thus challenged the old Byzantine tradition of placing Greeks on the episcopal sees.
Hilarion's appointment met with stiff opposition from Luka Zhidiata, Bishop of Novgorod (r. 1035-1060). Zhidyata openly opposed probably because it was the prerogative of the Patriarch of Constantinople to appoint the Kievan metropolitan and thus Hilarion's appointment was uncanonical. For his opposition, Luka was confined in the Kievan Caves Monastery for three years until his death, at which time his remains were taken back to Novgorod and buried in the Cathedral of Holy Wisdom there.