The third quarter of the tenth century witnessed a great recrudescence of the power of Constantinople under the Emperor Nikiphóros Phokas, who wrested Cyprus and Crete from the Arabs and inaugurated an era of prosperity for the eastern empire, giving it a new lease of vigorous and combative life. Wishing to reassert the Greek supremacy in the Balkan peninsula his first act was to refuse any further payment of tribute to the Bulgarians as from 966; his next was to initiate a campaign against them, but in order to make his own success in this enterprise less costly and more assured he secured the co-operation of the Russians under Svyatoslav, Prince of Kiev; this potentate’s mother Olga had visited Constantinople in 957 and been baptized (though her son and the bulk of the population were still ardent heathens), and commercial intercourse between Russia and Constantinople by means of the Dnieper and the Black Sea was at that time lively. Svyatoslav did not want pressing, and arriving with an army of 10,000 men in boats, overcame northern Bulgaria in a few days (967); they were helped by Shishman and the western Bulgars, who did not mind at what price Peter and the eastern Bulgars were crushed. Svyatoslav was recalled to Russia in 968 to defend his home from attacks by the Tartar Pechenegs, but that done, he made up his mind to return to Bulgaria, lured by its riches and by the hope of the eventual possession of Constantinople. The Emperor Nikiphóros was by now aware of the danger he had imprudently conjured up, and made a futile alliance with eastern Bulgaria; but in January 969 Peter of Bulgaria died, and in December of the same year Nikiphóros was murdered by the ambitious Armenian John Tzimisces,[1] who thereupon became emperor. Svyatoslav, seeing the field clear of his enemies, returned in 970, and in March of that year sacked and occupied Philippopolis. The Emperor John Tzimisces, who was even abler both as general and as diplomat than his predecessor, quietly pushed forward his warlike preparations, and did not meet the Russians till the autumn, when he completely defeated them at Arcadiopolis (the modern Lule-Burgas). The Russians retired north of the Balkan range, but the Greeks followed them. John Tzimisces besieged them in the capital Preslav, which he stormed, massacring many of the garrison, in April 972. Svyatoslav and his remaining troops escaped to Silistria (the Durostorum of Trajan) on the Danube, where again, however, they were besieged and defeated by the indefatigable emperor. At last peace was made in July 972, the Russians being allowed to go free on condition of the complete evacuation of Bulgaria and a gift of corn; the adventurous Svyatoslav lost his life at the hands of the Pechenegs while making his way back to Kiev. The triumph of the Greeks was complete, and it can be imagined that there was not much left of the earthenware Bulgaria after the violent collision of these two mighty iron vessels on the top of it.