On his journey home from this long expedition, Sviatoslav finished what he undertook when he started: he subjected the Vyatichi on the Oká, and forced them to pay tribute. At this juncture the Greek Emperor, Nikifor, threatened on one side by the Bulgarians and on the other by the Arabs, sent envoys to Sviatoslav with much gold and many promises. “Let the Russian prince attack the Bulgarians,” said the envoys. “Let him take their land, let him keep it if he wishes.” Following this suggestion, Sviatoslav, in 967, overran the greater part of Bulgaria, and wished to remain in the country, taking Pereyaslavets on the Danube as his capital. But while Sviatoslav was ruling Bulgaria from his place on the Danube, the Petchenegs, who had hitherto been kept down by the Kazars, rushed to Kief and laid siege to it so closely that no man could enter the city or leave it. At last means were found to inform Sviatoslav, who hurried home with men and scattered the besiegers, driving them far out into the steppe. Olga, his mother, then in old age, died three days after his coming. Sviatoslav now instated his sons as princes in Russia. He established his eldest son, Yaropolk, in Kief; his second son, Oleg, he sent to the Drevlians; Vladimir, the third and youngest son, went to Novgorod at the request of its citizens, who were advised by Dobrinya, his uncle, to demand him of his father. Sviatoslav, now free, went back to Bulgaria, but he did not meet the same fortune as before. The Bulgarians received him with weapons in their hands and gave battle immediately, but they were defeated, after a desperate struggle, and their town was taken by storm. Then appeared a far more formidable enemy, the Byzantine Emperor, John Zimisces, with an overwhelming army. The Russians were terrified, but Sviatoslav strengthened them, saying: “We have no escape. Whether we will or not, it has come to us to stand against the Greeks. Let us not bring an evil name upon the Russian land, but leave our bones upon the field; for the dead there is no disgrace. If we flee we shall find no hiding-place from our shame. Stand firmly together!” A mighty struggle began. According to the Greeks, the Russians were overcome; according to the Russians, the Greeks yielded. Whoever gained the victory, Sviatoslav, before leaving Bulgaria, concluded a treaty by which he agreed not to attack Byzantine territory or permit others to do so. The Emperor sent rich gifts to Sviatoslav and had an interview with him, evidently thinking the friendship of such a man better than his enmity.