Elevation to the See of Kiev
Hilarion served as a priest at the Church of the Holy Apostles in Berestove, a princely residence near Kiev, where he gained a reputation as an educated scholar, a gifted preacher, and a writer. He was also spiritual father to Grand Prince Yaroslav the Wise.
Following the death of Metropolitan Theopemptus (c. 1049), Hilarion was proclaimed Metropolitan in 1051 by a council of local Russian bishops at the proposition of Yaroslav the Wise. This was a deliberate challenge to the Byzantine tradition by which the Patriarch of Constantinople appointed Greeks to the Kiev see; Patriarch Michael I Cerularius was not involved in the appointment. By some accounts the Patriarch of Constantinople later confirmed the appointment.
Sources record that he codified the governance of church life in Kievan Rus' and defended the independence of the church against the hierarchs of Constantinople. His tenure was brief: the chronicles begin mentioning Metropolitan Yefrem (Efrem) as holder of the Kiev see in 1055, and Hilarion is thought to have died around 1053, before Yaroslav's death in 1054.
The Sermon on Law and Grace
Hilarion's principal surviving work is the Sermon on Law and Grace (also called the Discourse Concerning Law and Grace), composed between roughly 1037 and 1050 on the basis of cross-references with the Primary Chronicle. It was likely delivered at Kiev's Tithe Church and addressed to the Christian elite of Kievan Rus'.
The sermon has two distinct parts. The first presents a theological contrast arguing that the grace of the New Testament surpasses and replaces the law of the Old Testament. Hilarion uses biblical allegory, comparing Isaac (representing Christians) to Ishmael (representing Jews), and draws on the Apostle Paul's imagery of Abraham's two wives — Sarah, the freeborn, and Hagar, the slave — to explain the relationship of the Old and New Covenants, writing that 'the Law fades at the shining forth of grace.'
The second part is a panegyric to Vladimir the Great, the baptizer of Rus', possibly intended to support Vladimir's canonization. The Sermon ranks among the earliest available Slavonic texts, predating the Primary Chronicle by decades, and Hilarion came to be regarded as a writer worthy of imitation who shaped both the style and content of later literature in Kievan Rus'.
Connection to the Kiev Caves
According to the chronicler Saint Nestor, Hilarion made his way from Berestove to the Dnieper and dug out a shallow cave, some fourteen feet deep, where he engaged in monastic prayer and contemplation. This cave was at the location that would become the Kiev Caves Monastery.
He was buried in the Kiev Caves and is numbered among the Kiev Caves saints. He appears in the Synaxis of the Fathers of the Near Caves (September 28) and in the service of all Kiev Caves Saints (the second Sunday of Great Lent).
Writings
Beyond the Sermon on Law and Grace, several works are credited to Hilarion. He composed an episcopal Confession of Faith that became a model for the vows of Russian bishops, a Sermon on Spiritual Benefit to All Christians, and The Prayer of Saint Hilarion; some lists also attribute to him a work addressed to stylite brethren (Words to my brother Stylites).
Traditional Accounts
A theory advanced by the Russian historian Mikhail Prisyolkov in the 1920s holds that Hilarion later became a monk under the name Nikon, settled in the Kiev Caves Monastery, and may be the same Nikon who compiled the so-called 1073 Caves Chronicles. This remains a scholarly hypothesis rather than established fact.
Accounts of the precise dates of his tenure vary: while 1051 is given for his elevation, the end of his metropolitanate is variously placed at 1052, 1053, or about 1055, with the chronicles naming his successor Efrem by 1055.
