End of the war[edit]
With no Persian army left to oppose him, Heraclius' victorious army plundered Dastagird, which was a palace of Khosrau's, and gained tremendous riches while recovering 300 captured Byzantine flags.[138] Khosrau had already fled to the mountains of Susiana to try to rally support for the defense of Ctesiphon.[113][114] Heraclius then issued an ultimatum to Khosrau:
I pursue and run after peace. I do not willingly burn Persia, but compelled by you. Let us now throw down our arms and embrace peace. Let us quench the fire before it burns up everything.
— Heraclius' ultimatum to Khosrau II, 6 January 628[139]
However, Heraclius could not attack Ctesiphon itself, as the Nahrawan Canal was blocked due to the collapse of a bridge leading over it,[138] and he did not attempt to bypass the canal.[140]
Regardless, the Persian army rebelled and overthrew Khosrau II, raising his son Kavadh II, also known as Siroes, in his stead. Khosrau was shut in a dungeon, where he suffered for five days on bare sustenance—he was shot to death slowly with arrows on the fifth day.[141] Kavadh immediately sent peace offers to Heraclius. Heraclius did not impose harsh terms, knowing that his own empire was also near exhaustion. Under the terms of the peace treaty, the Byzantines regained all their lost territories, their captured soldiers, a war indemnity, and most importantly for them, the True Cross and other relics that were lost in Jerusalem in 614.[141][142][143]