The year A.D. 527 seems to have been one in which nothing of importance was attempted on either side. At Constantinople the Emperor Justin had fallen into ill health, and, after associating his nephew Justinian on the 1st of April, had departed this life on the 1st of August. About the same time Kobad found his strength insufficient for active warfare, and put the command of his armies into the hands of his sons. The struggle continued in Lazica, but with no decisive result. At Daras, Belisarius, apparently, stood on the defensive. It was not till A.D. 528 had set in that he resumed operations in the open field, and prepared once more to measure his strength against that of Persia. Belisarius was stirred from his repose by an order from court. Desirous of carrying further the policy of gaining ground by means of fortified posts, Justinian, who had recently restored and strengthened the frontier city of Martyropolis, on the Nymphius, sent instructions to Belisarius, early in A.D. 528, to the effect that he was to build a new fort at a place called Mindon, on the Persian border a little to the left of Nisibis. The work was commenced, but the Persians would not allow it to proceed. An army which numbered 30,000 men, commanded by Xerxes, son of Kobad, and Perozes, the Mihran, attacked the Roman workmen; and when Belisarius, reinforced by fresh troops from Syria and Phoenicia, ventured an engagement, he was completely defeated and forced to seek safety in flight. The attempted fortification was, upon this, razed to the ground; and the Mihran returned, with numerous prisoners of importance, into Persia.