Theodore the Black, 13th-century Prince of Yaroslavl, Smolensk and Mozhaysk, who ended his life as a monk and deeply repented his alliance with Mongol invaders Theodore the Varangian and his son John, the first known martyrs in Rus' Theodosius of Kiev, co-founder of the Kiev Pechersk Lavra, the first monastery in Russia Theophan the Recluse, major 19th-century theologian who played an important role in translating the Philokalia from Church Slavonic into Russian Therapont of White Lake, founder of Ferapontov Monastery Tikhon of Kaluga, founder of the Dormition of the Mother of God Monastery in Kaluga Tikhon of Moscow, Patriarch of Moscow and all Russia, notable missionary, fighter against the so-called Living Church, first saint of the 20th century, who canonized of Russian Orthodox Church Tikhon of Zadonsk, bishop and spiritual writer, the most important 18th-century religious educator in Russia Tryphon of Pechenga, founder of the Pechenga Monastery on the Kola Peninsula V Vladimir I of Kiev "the Great", Kievan Prince who turned from pagan to saint and enacted the Christianization of Kievan Rus' Vsevolod of Pskov, medieval Prince and a patron saint of Pskov X Xenia of Saint Petersburg, fool for Christ, patron saint of St Petersburg who gave all her possessions to the poor and wandered for 45 years around the streets Xenophon of Robeika, 13th-century monk, hermit and hegumen of the Khutyn Monastery Y Yegor Chekryakovsky, priest and a starets, spiritual heir of Saint Ambrose of Optina Yuri II of Vladimir, Grand Prince of Vladimir during the Mongol invasion of Rus', died in the Battle of the Sit River Z Zosima of Solovki, one of the founders of the Solovetsky Monastery See also List of Metropolitans and Patriarchs of Moscow List of saints List of American Eastern Orthodox saints List of saints of the Canary Islands Saints Russian Saints Saints Saints