The Greek historians also allege that Sviatoslav agreed to support Kalokyros in his ambition of gaining the imperial throne, while Kalokyros promised to reward Sviatoslav with "great, incalculable treasures from the imperial coffers" and to acknowledge his conquest of Bulgaria.
The Greek historians assert that Sviatoslav agreed to assist Kalokyros in his quest for the imperial throne, with Kalokyros promising to reward Sviatoslav with substantial riches and acknowledge his conquest of Bulgaria.