 Complete the following phrase:  In spring 531, as news arrived of another Persian invasion, Hermogenes was sent again to the East at the head of reinforcements for Belisariuss army. He joined Belisarius, who had been following the Persians, at Barbalissus. There, Hermogenes mediated and resolved a dispute between Belisarius and one of his subordinate commanders, Sunicas. At this point the Persians, confronted by the Byzantine army, decided to withdraw. Hermogenes agreed with Belisariuss opinion that, their invasion having failed, they should be allowed to do so, but his subordinate commanders advocated battle. The two armies met near Callinicum, but the ensuing 