In 528, war between the Sasanians and Byzantines erupted again, because of the Byzantines refusal to acknowledge Khosrow as Kavad's heir, and a dispute over Lazica. Although Kavad's forces suffered two notable losses at Dara and Satala, the war was largely indecisive, with both sides suffering heavy losses. In 531, while the Iranian army was besieging Martyropolis, Kavad died from an illness. He was succeeded by Khosrow I, who inherited a reinvigorated and mighty empire that equaled that of the Byzantines.