The Holy Prince Igor of Chernigov: The mid-twelfth century was a grievous time of incessant internecine strife over the Kiev principality between two princely factions: the Olegovichi and the Mstislavichi. They were all close relatives, they were all great-grandsons of Yaroslav the Wise. The Mstislavichi were called after their father, Saint Mstislav the Great (April 15), son of Vladimir Monomakh (from whence their other name: “Monomashichi”). The Olegovichi were called after the name of Oleg Sviatoslavich (+ 1115), known as “Gorislavich” because of his bitter [“gore”] fate. Oleg Gorislavich was the son of the Kievan prince Sviatoslav (+ 1076), who participated in the Transfer of the Relics of the holy Passion-Bearers Boris and Gleb in the year 1072 (May 2). Sviatoslav was the owner of two of the most remarkable theological collections of this time -- the “Sviatoslav Izbornik [selections from the holy Fathers] of 1073” and the “Izbornik of 1076.”