Without losing time, Knyaz Boris asked the Pope to appoint Formosus of Portus, who years later became Pope Formosus, as Bulgarian archbishop. The Pope refused, with the official response being that Formosa already had an eparchy. The Pope ordered new leaders, Dominic of Trivena and Grimwald of Polimarthia, of a mission to be sent to Bulgaria. Soon after, Nicolas died. His successor, Pope Adrian II (867-872), also failed to respond to Knyaz Boris' request for appointment of a Bulgarian archbishop. Knyaz Boris proposed another candidate for Bulgarian archbishop, Marinus. Deacon Marinus at this time was a papal legate in Constantinople and did not have an eparchy, but the Pope refused. Instead, he received a cleric named Silvester, a man so low in the hierarchy that was not authorized to carry out liturgy by himself. After he had a three-day stay in Pliska, the Bulgarians sent him back to Rome accompanied by emissaries carrying a letter of complaint by Knyaz Boris. Boris perceived Rome's refusals of his request and delays as an insult and a sign of the Pope's unwillingness to coordinate selection with him of a Bulgarian archbishop. Marinus became Pope just a few years later with the name Pope Marinus I. As a result, Boris began negotiations again with Constantinople, with whom he expected more cooperation than shown in the past. But, on 23 September 867, Emperor Michael III was killed by his close acquaintance Basil, who established the Macedonian dynasty that ruled the Empire until 1057. Patriarch Photius was replaced by his ideological rival Ignatius (847-858; 867–877). The new rulers of the Byzantine Empire quickly lessened tensions between Constantinople and Rome. Pope Adrian II needed the help of Basil I against the Arabs' attacks in Southern Italy. On the other hand, Byzantium anticipated the Pope's support for Patriarch Ignatius. Result As a result of the leaders' agreements, a Church Council was held in Constantinople. After the end of the official conferences, on 28 February 870 Bulgarian emissaries arrived in Constantinople, sent by the Knyaz and led by the Ichirguboil (the first councilor of the Knyaz) Stasis, the Kan-Bogatur (high-ranking aristocrat) Sondoke, the Kan-Tarkan (high-ranking military commander) among others. Few people suspected the real purpose of these emissaries. On 4 March Emperor Basil I closed the council with a celebration at the Emperor's palace. In attendance was the Bulgarian Kavkan (roughly a vicekhan or viceknyaz) Peter. After he greeted