The two sons of Vladimir Monomach renowned in history are Mystislav the Great, and Yuri, surnamed Dolgoruki. From the first comes the elder, from the second the younger line of Monomach’s descendants. Mystislav became the ancestor of the Western Russian princes, those of Galitch (Galicia), Smolensk and Volynia. Yuri, through the founding of Moscow and the results flowing from it, became the father of that northern line of princes so famous in history. The descendants of these two brothers were often at enmity, and it was their rivalry which later on ruined Kief. Mystislav succeeded his father in 1125 without opposition. Oleg of Chernigoff had died during Monomach’s reign, so had David, his brother. Only Yaroslav, the youngest brother, now remained. He, not greatly considered in his family, was expelled from Chernigoff by Vsevolod, his nephew, and founded in Ryazan a new principality. Mystislav’s reign was distinguished for three things. First he brought to order those Polovtsi who would live in peace near the boundary, and crushed or expelled the others; then he seized all lands of the Polotsk princes, the descendants of Rognyeda, that unwilling wife of Vladimir (Saint Vladimir of the Orthodox Church). We have seen how those Polotsk princes, when excluded from the Kief succession, harried Smolensk and raided Novgorod, bringing ceaseless trouble and never-ending bloodshed. Later on both Pinsk and Turoff had been taken from them. This intensified resistance, and, as they would abate no claim whatever, Mystislav resolved at last to end the trouble. He captured all those princes and, putting them on a vessel, sent them to Tsargrad, where the Emperor, his friend, detained the captives. Some died; the survivors, or most of them, escaped in later days, and ruled again in parts of Polotsk, but soon were lost to fame, unless the tradition be true that Gedimin and his sons, who seized Western Russia during Mongol dominion and joined it with Poland through marriage, were descended from those Polotsk princes who returned from Tsargrad. A third event in Mystislav’s reign was the founding of Ryazan, which happened in this way. Oleg of Chernigoff, who died during Monomach’s reign, was succeeded by his youngest brother, Yaroslav. Of Oleg’s sons the second, Vsevolod, later on the Kief prince, was a man who in early life had planned a great career very carefully. He had married the eldest daughter of Mystislav the Great, and had thus become connected with Monomach’s descendants. When Mystislav succeeded Monomach, his father, in Kief, Vsevolod drove his uncle from the throne of Chernigoff, and seated himself there. Vsevolod was unceremonious with Yaroslav because the man was not strong, and because he himself wanted Kief when the time came to get it. To possess Kief, he must first win, or get Chernigoff, hence must drive out his uncle.