For Usbek, after having preferred and supported the rights of Michael of Tver to the grand principality, had changed his mind in favour of Iuri of Moscow, who had become his brother-in-law. The enmity of Usbek, however, remained suspended, until his sister, the wife of Iuri, and the prisoner of Michael, expired at Tver. Iuri then hastened to the horde, and accused Michael of having poisoned the princess. The offended pride of Usbek lent itself to this base calumny; he entrusted the investigation of the affair to Kavadgi; appeared to the summons; the vanquished passed sentence on his vanquisher, whom he caused to be put to death; and the infamous Iuri of Moscow was appointed grand prince in the place of his murdered rival (1320). His triumph was short: being accused of withholding the tribute due to the khan, he journeyed to the horde, and was assassinated by the son of his victim, who was himself immediately executed by Usbek. This vengeance restored the grand principality to the branch of Tver, in the person of Prince Alexander Michael’s second son. It remained in it for three years; but then, in 1328, this madman caused all the Tatars at Tver to be massacred. To the brother of Iuri, Ivan I, surnamed Kalita,[13] prince of Moscow, Usbek immediately gave Vladimir and Novgorod, the double possession of which always distinguished the grand princedom. This concession formed, in the hands of Ivan, a mass, the connection of which Tver, weakened as it was, did but little diminish. Consequently, with this power, and the troops that Usbek added to it, Ivan speedily compelled all the Russian princes to combine, under his orders, against the prince of Tver; who, after having undergone various misfortunes, was executed with his son at the horde. Here begin the two hundred and seventy years of the reign of the branch of Moscow. This first union of the Russians, under Ivan I, denominated Kalita, constitutes an epoch; it exhibits the ascendancy of this second grand prince of Moscow over his subjects; an ascendancy the increase of which we shall witness under his successors; and for which, at the outset, this branch of the Ruriks was indebted to the support they received from the Tatars. For as a word from the khan decided the possession of the throne, that one of the two rival branches of Moscow and Tver was sure to triumph which displayed the most shrewd and consistent policy towards the horde. It was not that of the princes of Tver which thus acted. On the contrary they sometimes solicited the protection of the khans, and sometimes fought against them; we have even seen one of them ordering the massacre of the Tatars in his principality.