Agents of the Italian cities came to seek Bayezid after the battle to congratulate him, and to ask for the confirmation of the commercial privileges granted by Murad. Bayezid showed himself proud and distant. He declared that after he had conquered Hungary he would ride so far that he would come to Rome and there give his horse oats to eat upon the altar of St. Peter’s.[436] A change of attitude towards Europe is strikingly revealed in this boast. Murad, in spite of crusades projected against him, had been careful not to draw upon himself the attention, much less the ill-will, of the western Christian princes. He was aggressive, but never any more so than he needed to be for the moment at hand: and he was never aggressively Mohammedan. Bayezid, from the very beginning of his reign, took no pains to conceal his enmity to Christendom, and his desire to pose as the champion of Islam. He sought alliances with the Sultan of Egypt[437] and other Moslem rulers, and placed the utmost importance upon the extension of Ottoman sovereignty in Asia Minor. II After the bloodthirst of Kossova had been satisfied and his father’s death avenged, Bayezid was eager to enter into friendly relations with Stephen Bulcovitz, son and heir of Lazar. He felt that the Serbians had learned their lesson, and that they would be more helpful to him as allies than as crushed and sullen foes. He needed their aid in the Anatolian campaign which he was contemplating, and they were essential to the safety of his European possessions as a buffer against the Hungarians, who he knew would take the opportunity of his absence in Asia to move down the Danube. So he treated Stephen and the surviving Serbians with great kindness. Stephen received all the privileges that had belonged to his father.[438] The Serbians were assured of an equitable share of the booty in the campaigns in which they would engage. On the other hand, Stephen agreed to allow Bayezid an annual tribute, secured by the revenues of the silver mines, to command a contingent in person in the Ottoman army, and to give his sister to the Ottoman emir.[439] Kossova was forgiven on both sides.