sentences:  The city was apparently held by the Bulgarian Empire at some point in the late 9th century.The 11th-century Greek bishop Theophylact of Ohrid wrote that during the brief period of Bulgarian dominance, Tsar Boris I built there one of the seven cathedral churches built by him and refers to it as "one of the beautiful Bulgarian churches".In the "Escorial Taktikon" of , the city is mentioned as the seat of a "strategos", and it apparently was the capital of a theme in the 11th century.