When this hereditary protection afforded by the grand princes of the Moscow branch was once fairly established, the nobles of each appanage, who constituted its army, had thenceforth an asylum, and, as it were, a tribunal for redress, to which they could appeal whenever they were dissatisfied with their prince. It was this which made Tver fall before Ivan Kalita; for the sovereign prince of that first and last rival of Moscow having preferred to his boyars the people of Pskov, who had defended him, the former withdrew to Moscow. The power of Ivan Kalita being once raised by the Tatars’ aid, and by the re-establishment of the direct line of succession, and thoroughly developed by his son and grandson, Simeon the Proud and Dmitri Donskoi, it followed, as a natural consequence, that he who was most able to reward and to punish drew around him, and retained, the whole of the nobles. These constituted the sole strength of the appanaged princes; their defection, therefore, completed the subjugation of the princes. Dmitri Donskoi was, therefore, in reality sovereign, as is proved by his treaties with the princes who held appanages, all of whom he reduced to be his vassals. And, accordingly, notwithstanding the appanages which he gave to his sons, and the dissensions which arose out of that error--an error as yet, perhaps, unavoidable--the attachment of the nobles, for which we have just assigned a reason, always replaced the legitimate heir on the throne. [Sidenote: [1366 A.D.]] Already, so early as about 1366, the Russian princes could no longer venture to contend against their lord paramount by any other means than by denunciations to the horde; but to what khan could they be addressed? Discord had created several: what result was to be hoped from them? Divided among themselves, the Tatar armies had ceased to be an available force. The journeys to the Golden Horde, which had originally contributed to keep the Russian princes in awe, now served to afford them an insight into the weakness of their enemies. The grand princes returned from the horde with the confidence that they might usurp with impunity; and their competitors with envoys and letters, which even they themselves well knew would be of no avail. It was, then, obvious in Russia, that the only protecting power was at Moscow: to have recourse to its support was a matter of necessity. The petty princes could obtain it only by the sacrifice of their independence; and thus all of them became vassals to the grand prince Dmitri.