Theodosius of Kiev

Theodosius of Kiev or Theodosius of the Caves (; ) is an 11th-century saint who brought Cenobitic Monasticism to Kievan Rus' and, together with Anthony of Kiev, founded the Kyiv Caves Lavra (Monastery of the Caves). A hagiography of Theodosius was written in the twelfth century.
Theodosius' greatest achievement has been the introducing of the monastic rule of Theodore the Studite in the Monastery of the Caves whence it spread to all the monasteries of the Ukrainian and Russian Orthodox Church. According to the "Primary Chronicle":
Theodosius has been glorified (canonized) as a saint by the Russian Orthodox Church. His main feast day is May 3, the date of his repose. His relics were discovered by Nestor the Chronicler, on August 14, 1091, and were found to be incorrupt. The relics were transferred to the main catholicon (cathedral) of the monastery, and a second annual feast day was established in commemoration of this event.