brother was reached and then succession transferred back to the elder prince's son. Unfortunately for the Kievians, when Vladimir died, there was no clear line of succession and political infighting ensued; the resulting anarchy and civil war made trade difficult and invasion inevitable. Politically, the structure of the Kievan Federation left the people without the tools necessary to ward off invaders and prosecute a winnable war. The aristocracy had no real power to deal with foreign states and there was no seat of true power as was found in feudal Europe. The Kievan Federation lacked the land-grant vassal—lord system which made England and France strong. In those two states, the king granted land to his loyal knights in return for cooperation, loyalty and tax revenue. The knight, or vassal, would then parcel the land out to renters or serfs, in order to bring in wealth. The king offered protection to the knight by control of an army to ward off invaders and the knight afforded safety to the serfs by local protection. The Kievan federation, however, took the path of the German Empire and still contained characteristics of city-state independence; the individual family communes still thought of themselves as independent entities. In Europe as often happened, independent states often banded together and formed a strong central power in efforts to achieve a common goal, such as defense. Unfortunately for the people of Rus' they found themselves with no strong government, no clear successor, and no foreseeable way to ward off the invasions of its enemies. Tatar invasions 1237 marked the beginning of a period of decline for the Rus', as both a culture and as a people. The first through Fourth Crusade, which effectively halted trade with the Byzantine Empire and cut off the Middle Eastern trade routes, began the decline of Kievan importance. The Mongol invasion of 1237 also helped mark the passing of free Kievian society. The Tatars sacked Kiev and all major towns; their practice of total destruction led to the dismemberment of the Kievian princedom and an end to Russian society as their people knew it. With the annihilation of Kiev and every city west of it all the way into Central Europe, Russian trade with the west and south was curtailed. With the destruction of its trade base and its trade routes curtailed, Kiev's role as an important seat of power ended. The people found