 Complete the following phrase:  After the victory Simeon I sent letters to the Ecumenical Patriarch Nicholas Mystikos and Romanos co-emperor Constantine VII to propose peace negotiations. However, his intention was to prolong the negotiations until the return of his envoys to the Fatimids. While Simeon I and Nicholas Mystikos exchanged letters the military actions continued. In a few weeks the Bulgarian army captured Adrianople, the most important city in Byzantine Thrace. The fall of Adrianople raised fears in Constantinople that a Bulgarian assault of the city was imminent. The Byzantines tried to intimidate Simeon I by threatening to incite the Magyars, the Pechenegs and Kievan Rus to attack Bulgaria from the north-east, as they had done in the 