Michael VII was very worried about events in the Balkans, and wanted to associate with himself a good and experienced military man, offering the position of kaisar (formally vacated by the tonsured Ioannes Doukas). He and Nikephoritzes agreed to make Nikephoros Bryennios kaisar and doux of all Bulgaria, with the task of subduing the whole people of the Slavs. Bryennios was summoned from Thrace to Constantinople, despite the disagreement of Konstantinos (nephew of Keroularios) with this decision: Konstantinos was said to covet the position for himself