Scholars have disputed whether agriculture or commerce was economically more important in Kievan Russia; the answer appears to be commerce. In trade, with Byzantium in particular, the Russians sold mostly furs, honey, and wax—products not of agriculture but of hunting and beekeeping. Since the Byzantines paid in cash, Kiev had much more of a money economy than did western Europe. From the economic and social point of view, Kievan Russia in the eleventh century was in some ways more advanced than manorial western Europe.
Before the Tatar invasions, which started in the early 1200s, the Kievan state began to have close diplomatic and political relations with the West. Dynastic marriages were arranged between the ruling house of Kiev and the royal families of Sweden and France, and alliances were reached with the states of Germany. Merchants from the West appeared in Russia, especially at Novgorod and at Kiev. Whatever isolation was imposed by Byzantine Christianity might have been overcome had Kiev been allowed to maintain its free lines of communication and its vigorous and valuable exchange from the West. But Russia was denied this opportunity.
The Kievan state had many internal political weaknesses. It failed to make any rules for the succession to the throne, and it followed the practice of dividing the land among a prince’s sons. The resulting fragmentation into often mutually hostile provinces weakened the state. Thus when the Mongol Tatars appeared in the early thirteenth century, Kievan Russia had been softened for the blow.
Never entirely centralized politically, the Kievan state nonetheless strove for unity. It bequeathed the ideal of unity, together with a literary language and a single Christian faith, to the future Russian state of Muscovy (Moscow) that was to emerge after more than two centuries of Mongol domination. Moscow would take from the Byzantines not only their religion but also their political theory of autocracy.