When was the last Bulgarian noble surrendered to the Byzantine Empire?

From ca. 970 until 1018, a series of conflicts between the Bulgarian Empire and the Byzantine Empire led to the gradual conquest of Bulgaria by the Byzantines, who thus re-established their control over the entire Balkan peninsula for the first time since the 7th-century Slavic invasions. The struggle began with the incorporation of eastern Bulgaria after the Russo–Byzantine War (970–971). Bulgarian resistance was led by the Cometopuli brothers, who based in the unconquered western regions of the Bulgarian Empire led it until its fall under Byzantine rule in 1018.