Hostility between the two powers erupted into conflict once again in 528, just a year after the new Byzantine emperor Justinian I (r. 527–565) had been crowned.
This was supposedly the result of the Byzantines not acknowledging Khosrow as Kavad's heir.
According to the Greek chronicler John Malalas, military clashes first took place in Lazica, which had been disputed between the two empires since 522.
Not long after this the battles also spread down to Mesopotamia, where the Byzantines suffered a heavy defeat near the border.
In 530, one of the famous open-field battles took place between the Byzantine and Sasanian troops at Dara.

The Sasanian army led by Perozes, Pityaxes and Baresmanas suffered a severe defeat.
The battle did not, however, bring an end to the conflict.
The following year Kavad raised an army, which he sent under Azarethes to invade the Byzantine province of Commagene.
When the Byzantine army under Belisarius approached, Azarethes and his men withdrew east, halting at Callinicum.
In the ensuing battle the Byzantines suffered a heavy defeat, but Iranian losses were so great Kavad was displeased with Azarethes, and relieved him of his command.
In 531, the Iranians besieged Martyropolis.
During the siege, however, Kavad became ill and died on 13 September.
As a result, the siege was lifted and peace was made between Kavad's successor Khosrow I and Justinian.
Hostility between the two powers erupted into conflict once again in 528, just a year after the new Byzantine emperor Justinian I (r. 527–565) had been crowned. This was supposedly the result of the Byzantines not acknowledging Khosrow as Kavad's heir. According to the Greek chronicler John Malalas, military clashes first took place in Lazica, which had been disputed between the two empires since 522. Not long after this the battles also spread down to Mesopotamia, where the Byzantines suffered a heavy defeat near the border. In 530, one of the famous open-field battles took place between the Byzantine and Sasanian troops at Dara.
The Sasanian army led by Perozes, Pityaxes and Baresmanas suffered a severe defeat. The battle did not, however, bring an end to the conflict. The following year Kavad raised an army, which he sent under Azarethes to invade the Byzantine province of Commagene. When the Byzantine army under Belisarius approached, Azarethes and his men withdrew east, halting at Callinicum. In the ensuing battle the Byzantines suffered a heavy defeat, but Iranian losses were so great Kavad was displeased with Azarethes, and relieved him of his command. In 531, the Iranians besieged Martyropolis. During the siege, however, Kavad became ill and died on 13 September. As a result, the siege was lifted and peace was made between Kavad's successor Khosrow I and Justinian.
Kavad I