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In page Battle of Nineveh (627):

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With no Persian army left to oppose him, Heraclius' victorious army plundered Dastagird, Khosrau's palace, and gained tremendous riches while recovering 300 captured Byzantine/Roman standards accumulated over years of warfare.[2] Khosrau had already fled to the mountains of Susiana to try to rally support for the defense of Ctesiphon.[3][4] Heraclius could not attack Ctesiphon itself because the Nahrawan Canal was blocked by the collapse of a bridge.[2]