sentences:  In 578, the truce in Mesopotamia came to an end and the main focus of the war shifted to that front.After Persian raids in Mesopotamia, the new "magister militum" of the East Maurice mounted raids on both sides of the Tigris, captured the fortress of Aphumon and sacked Singara.Khosrow again sought peace in 579, but died before an agreement could be reached and his successor Hormizd IV (r. 579–590) broke off the negotiations.