These successes and the skilful policy of the grand prince made the most favourable impression on the mind of the khan, who now, whenever dissensions arose amongst the princes, either referred the adjustment of their differences to Alexander, or confiscated their dominions and annexed them to the grand princedom. Two instances of the latter description may be recorded as evidences of the cunning displayed by the Tatar in the protection of the Greek religion. While Alexander was at the height of his prosperity, the prince of Kiev, affected by some sudden admiration of the Roman Catholic ritual, signified his submission to the pope, acknowledging his holiness’s supremacy over the churches of his principality. Another prince, his brother-in-law, adopted a similar measure, which was equally offensive to Tatars and Russians. The khan, irritated by proceedings so directly at variance with his will, deprived them of their authority, and transferred their territories to the grand prince, who, according to some writers, was even assisted by the Tatars in seizing upon them. The tribute which had been originally imposed upon the Russians by their conquerors had always been levied by the princes, the khan being satisfied to receive it at their hands. As the power of Alexander increased, the khan gradually recalled this system of delegation, and adopted a more strict and jealous mode of collection. The first contribution was raised upon the princes, as tribute money, and they were left to procure it amongst their subjects as well as they could. But it now assumed the shape of a tax on persons and property. In order to ensure the regularity of its payment, and protect the khan against evasions, Tatar officers were appointed in every district to attend exclusively to the rigid collection of the revenue. From this tax, which was imposed without distinction upon every Russian, and rated according to his means, the clergy alone were exempt: and even they, in one instance, were attempted to be taxed in later times; but the khan who sought to enforce it was obliged to yield to the double argument of long-established usage and weighty presents from the wealthy monks.