Simeon, most submissive before the Khan, bought over the horde by using his father's treasure. To his brothers he was haughty and overbearing. As intermediary between the Tartars and Russian states he enjoyed privileges denied to his seniors, and arrogated to himself the title and position of "Prince of all the Russias." He continued his father's policy in Moscow, engaging Greek artists to ornament the cathedrals, and many native workmen to enlarge and improve the buildings within the Kremlin, spending upon Moscow the tribute he exacted from Novgorod and other towns. Ivan II. who succeeded him, 1353, was of quite another sort. Gentle, pacific, lovable--all outraged him; he would have lost his throne had not the church supported him loyally. Moris, a monk, quelled a revolt; a fire destroyed the Kremlin; when he died the succession to the title of Grand Duke, which his three predecessors had made such efforts to keep in the house of Moscow, passed to their kinsmen at Suzdal. Alexis, the metropolitan, saved the supremacy of Moscow. After crowning Dmitri at Vladimir he returned to Moscow to take charge of the children of Ivan II. and refused to leave the town. Dmitri was in his ninth year when he succeeded his father in Moscow, and remained in the tutelage of the church for many years. It was to the prompting of Alexis even more than to that of his own kinsmen that the breach of the Tartar alliance is due. Dmitri availed himself of a division in the Tartar horde to question the supremacy of either leader. Later he had the courage to visit Mamai--who was then the more powerful--and had the good luck to get back alive. Seven years later he won a battle against Mamai, in Riazan. In 1635 a fire on All Saints' Day destroyed the Kremlin wall and, a storm raging at the time, Moscow was almost in ruins. In 1367 the Kremlin was surrounded with a new wall--of masonry--and in the following year this was put to the test when an attack was made on Moscow by some bands of pagan Lithuanians under Olgerd, his brother Kistut and his subsequently famous nephew Vitovt. "Olgerd camped before the walls, pillaged the churches and monasteries in the neighbourhood, but did not assault the Kremlin, the walls of which frightened him." Two years later he returned to the attack, but his enterprise was unsuccessful. In the meantime Mamai, the Tartar leader, had matured his scheme of revenge. In 1380 he had collected his forces and was marching on Moscow when Dmitri, with the aid of all the neighbouring princes, got together an immense army and determined to give battle.