Nicephorus was a brave soldier, sprung from a stock of warlike Cappadocian landowners, who changed few of his habits even on the throne. He was cultured enough to write a book on the art of war, but he had neither the policy or pliancy for the intrigues of a despotic Oriental court. The uprightness he showed in preserving intact his step-sons’ position as Emperors met with an evil requital from their mother. Theophano hated and feared her stern, uncouth, unsympathetic husband. She conspired with her lover, John Zimisces, nephew of Nicephorus, a dashing cavalry soldier and the most capable of his captains. On the night of 10th December 969 the Empress’s woman admitted Zimisces and a select band of confederates into the castle. [Sidenote: Conspiracy of Theophano.] They found the Emperor sleeping on the floor after his soldier’s fashion, and promptly stabbed him to death. The murderers at once proclaimed John Zimisces Emperor, and court and city alike accepted the results of the despicable intrigue that had robbed the Empire of its strongest man. [Sidenote: John I. Zimisces, 969–976.] John I. Zimisces reigned from 969 to 976. The brutal treachery which gained him the throne was somewhat atoned for by the energy and vigour he displayed in the possession of power. He was mean enough to make Theophano the scapegoat of his crime, and, instead of marrying her, shut her up in a monastery. After this he did little that was not commendable. By way of penance he devoted half his private fortune to the poor peasantry round Constantinople, and to building a great hospital for lepers. Like Nicephorus, he studiously respected the rights of his young colleagues, the sons of Romanus II., and legitimatised his rule by wedding their sister Theodora. The negotiations for the marriage of the other sister, Theophano, with Otto the Saxon were now resumed and completed in 972, Theophano taking with her to Germany Byzantine art and the temporary friendship of east and west. [Sidenote: The Russian war.] John abandoned the civil administration to the dexterous chamberlain Basilius, and soon found in the Russian war an opportunity to revive the exploits of his uncle. The valour of Rurik and his Vikings had, before this, united the Slavs of the east into a single Russian state, of which the centre was Kiev, and which, though constantly threatening the Byzantine frontiers, had since the conversion of Olga, baptized at Constantinople in the days of Constantine VII., began slowly to assimilate Byzantine Christianity and civilisation. But Olga’s son Sviatoslav (964–972) had refused to incur the ridicule of his soldiers by accepting his mother’s religion. He was a mighty warrior who, in alliance with the Hungarians, overran and conquered Bulgaria, and in 970 crossed the Balkans and threatened Adrianople. In 971 John Zimisces took the field against him, and a desperate campaign was fought in the lands between the Danube and the Balkans. Like true sons of the Vikings, the