After his death the turbulence and confusion increased still further. His brother Rostislav of Smolensk was expelled after one week’s reign by the prince of Tchernigov, who was expelled in his turn by Iuri Dolgoruki. The latter might have shared the same fate, for a confederation of the princes of Smolensk, Tchernigov, and Volhinia had already been formed against him, but for his timely death (1157). One of the confederates ruled for eight months, and then he had to make room for his successor, who ruled four months. In the eighty-three years that elapsed between the death of Iuri and the capture of Kiev by the Mongols, the government changed hands thirty times. How much the importance of Kiev and the dignity of the grand princedom had declined at this period, we can estimate from the refusal of Andrew of Suzdal, son of Iuri Dolgoruki, to take the throne, though he came next in the line of succession. He rightly comprehended that the future belonged to the Russian north, rather than to the south, and it was his constant endeavour to consolidate his power in that quarter; and when one of those powerless grand princes, Mstislav Iziaslavitch, attempted to strengthen himself by forming an alliance with Novgorod, Andrew brought about a combination of eleven princes against him. After a three days’ siege Kiev was taken by assault and plundered for two days (March, 1169), and Andrew’s brother Gleb was then installed as grand prince of Kiev. The decay of the south is attributable chiefly to the following causes: (1) Its geographical position exposed it to the constant inroads of the nomads of the steppe. This evil, it is true, existed from remotest times, but its seriousness was increased by the action of the Russian princes themselves, who employed the nomads in their civil wars. Many of these nomads, Torks, Berendians, and Petchenegs, settled on the Ros and Dnieper, meddled in Russian affairs, and contributed to the barbarising of the country. (2) Every new grand-prince brought with him into Kiev a new following from his own principality. These foreign elements contributed ever anew to the unsettling of existing conditions, and prevented the growth of a landed aristocracy that had its roots in the soil, and of a burgher class. The establishment of a political tradition thus became impossible. (3) The trade with Greece had greatly declined owing to the increasing dangers of the journey to the sea, and more than once the princes were obliged to defend caravans to and from Byzantium with their entire army. [Sidenote: [1157-1175 A.D.]]