A siege of Constantinople followed the defeat and death of the Emperor Nicephorus. The Bulgars affrighted the defenders of the city by their fierce orgies before the walls, by the human sacrifices they offered up in their sight, and by the resolute refusal of all quarter in the field. The Empire tried to buy off the Bulgars with the promise of an annual tribute of gold, of cloth, and of young girls. The invaders finally retired with a great booty, and the death of King Kroum soon after relieved the anxiety of Constantinople. Bulgaria seems now (the ninth century) to have suffered again from internal dissensions. These arose mostly out of religious issues. Many of the Slavs had become Christians, and some of the Bulgars also adopted the new faith. For a time the kings tried to crush out Christianity by persecutions, but in 864 the Bulgarian King, Boris, adopted Christianity--some say converted by his sister, who had been a prisoner of the Greeks and was baptized by them. His adherence to Christianity was announced in a treaty with the Greek Emperor, Michael III. Some of King Boris's subjects kept their affection for paganism and objected to the conversion of their king. Following the customs of the time they were all massacred, and Bulgaria became thus a wholly Christian kingdom. King Boris, whom the Bulgarians look up to as the actual founder of the Bulgarian nation of to-day, hesitated long as to whether he should attach himself and his nation to the Roman or to the Greek branch of the Christian Church. He made the issue a matter of close bargaining. The Church was sought which was willing to allow to Bulgaria the highest degree of ecclesiastical independence, and which seemed to offer as the price of adhesion the greatest degree of political advantage. [Illustration: ANCIENT COSTUME OF BALKAN PEASANT WOMEN NEAR GABROVO] At first the Greek Church would not allow Bulgaria to have a Patriarch of her own. King Boris sent, then, a deputation to Pope Nicholas at Rome, seeking if a better national bargain could be made there. Two bishops came over from Rome to negotiate. But in time King Boris veered back to a policy of attaching himself to the Greek Church, which now offered Bulgaria an Archbishop with a rank in the Church second only to that of the Greek Patriarch. In 869 Bulgaria definitely threw in her lot with the Greek Church.