Complex sentence: The onset of the Succession Wars forced Blake to stop short of his goal of reforming the Terran Hegemony, but he was able to ensure total ComStar control over the Terran system.
Split into simpler sentences: The onset of the Succession Wars forced Blake to stop short of his goal of reforming the Terran Hegemony. He was able to ensure complete ComStar control over the Terran system.