Saint Mercurius of Kiev Caves Lavra was an ascetic in the Far Caves of Saint Theodosios during the XIV century, and was a strict observer of the Church's fasts.
He probably succeeded Bishop Lazarus as the Bishop of Smolensk, and with his flock, he experienced the horrors of Batu's invasion in 1347, during which he was killed. As he was dying, he ordered that the coffin containing his body should be sent down the Dnieper River and carried wherever it happened to land. Miraculously, the coffin came to rest at the Kiev Caves Monastery, and the Saint was buried in the Near Caves of Saint Anthony.
During his lifetime, Saint Mercurius had a deep spiritual bond with Saint Paisios of the Far Caves (July 19). When they died, they were buried in the same grave, but now their holy relics are in separate reliquaries.
Saint Mercurius, who glorified God by his words and his actions while on earth, now glorifies Him before His heavenly Throne.
The Church remembers Saint Mercurius on November 24 because of his patron Saint, the holy Great Martyr Mercurius. He is also commemorated on August 28 (the Synaxis of the Saints of the Far Caves); and on the second Sunday of Great Lent (the Synaxis of all the monastic Fathers of the Kiev Caves).