Khosrau intervenes in Lazica and supports the weakened king Gubazes II against a full-scale uprising.

He sends an expeditionary force under Miohr-Mihroe (Mermeroes in Byzantine sources) and captures the Roman stronghold of Petra, located on the coast of the Black Sea, which provides the Persians a strategic port.

Justinian sends an imperial army of thirty thousand to Armenia.

The Persians, severely outnumbered, are forced to retreat, but a force of four thousand ambushes the Romans at Dvin, completely routing and defeating the Roman forcess.

King Gubazes II revolts against the Persians and requests for aid from Justinian I.

He sends an expeditionary force of eight thousand men under Dagisthaeus, who together with a Lazic force lays siege to the Persian garrison at Petra.

As the Persians are well provisioned, the siege drags on.

Dagisthaeus has neglected to keep watch over the mountain passes that led into Lazica, and a far larger Persian relief force under Mihr-Mihroe arrives and raises the siege, yet the Persians lack sufficient supplies.

Mihr-Mihroe departs after strengthening the garrison at Petra and leaving a further five thousand men under Phabrizus to secure its supply routes.

Gubazes and Dagisthaeus combine their forces in the spring of 549 to destroy Phabrizus's army in a surprise attack; they pursue the survivors into Caucasian Iberia.

In the same summer, they win another victory against a new Persian army, led by Khorianes.

The allies fail, however, to prevent another Persian army from reinforcing Petra, and Dagisthaeus is recalled and replaced by Bessas.

The Sabir live predominantly in the region of Azerbaijan and Dagestan bounded on the east by the Caspian Sea, on the west by the Caucasus Mountains.

Priscus mentions that the Sabir attacked the Saragur, Urog and Unogur tribes in 461, forcing them North to the Volga once more, as a result of having themselves been attacked by the "Avars".

In 515, having recovered from the Avar attacks of the 460s, they "advertised their power in a huge raid south of the Caucasus, in which they attacked Iranian and Byzantine lands with scrupulous impartiality".

However, in the face of the increasing Avar threat, the Sabirs, previously allied with Sassanid Persia, switch their allegiance to Constantinople in 551 and invade the Caucasus.

The imperial army and their Sabir allies (some six thousand men) under Bessas recapture the strategic imperial fortress of Petra, located on the coast of the Black Sea.

Bessas orders the city walls razed to the ground, but a new army under Mihr-Mihroe is able to establish Persian control over the eastern part of Lazica.

The imperial forces in Lazica withdraw west to the mouth of the Phasis, while the Lazi, including Gubazes and his family, seek refuge in the mountains.

Gubazes, despite enduring harsh conditions in the winter of 551/552, rejects the peace offers conveyed by envoys from Mihr-Mihroe.

The Persians receive substantial reinforcements in 552, but their attacks on the fortresses held by Constantinople and the Lazi are repulsed.

Mihr-Mihroe had, through a ruse, succeeded in dislodging the imperial forces in 554 from Telephis, their most forward position, causing a general retreat along the Phasis river.

He had not pursued them, however, or otherwise pressed his advantage, due to his own army's lack of supplies.

After strengthening his own forts, he had returned to Mocheresis.

There he fell ill, and withdrew to Iberia; he dies of his illness at Mtskheta in the summer of 555.

Nachoragan is appointed the Persian commander-in-chief after the death of Mihr-Mihroe in 555.

He repulses the imperial attack on the Persian positions at Onoguris and forces the enemy out of Archaeopolis, a city which Mermeroes had twice tried and failed to take.

These defeats cause a bitter feud between the Lazic and imperial generals.

Over the past two years, Constantinople has increased its forces in Lazica, but failed to achieve decisive success; Gubazes had quarreled with their generals, and written to Emperor Justinian accusing them of incompetence following a defeat by the Persians.

Bessas had been recalled, but the other two, Martin and the sacellarius Rusticus, had resolved to get rid of Gubazes.

They sent a message to Constantinople accusing Gubazes of dealings with the Persians.

Emperor Justinian, intending to question Gubazes himself, had authorized the two generals to arrest him, using force if necessary.

In September/October 555, the two generals invite Gubazes to observe the siege of a Persian-held fort, but when they meet, John, Rusticus's brother, stabs the king with his dagger.

Gubazes falls from his horse, and one of Rusticus's servants gives him the finishing blow.

After Gubazes's murder, the Lazi stop participating in operations against the Persians for a time, leading to the failure of a Byzantine attack against the fort of Onoguris.

An assembly of the Lazic people informs Emperor Justinian of the events, requested that an investigation be launched, and asked that Gubazes's younger brother Tzath, at this time residing in Constantinople, be confirmed as their new ruler.

The emperor complies with their requests: a "leading senator" named Athanasius (perhaps the former praetorian prefect of the same name) is dispatched to investigate Gubazes's murder, and Tzath is sent to assume the Lazic throne.

Athanasius's investigation clears Gubazes of any suspicion of treachery; Rusticus and his brother John are found guilty and executed in autumn 556, but Martin is simply deposed from his post.

The allied Lazic and imperial forces in the ongoing war between the Sasanian and Roman empires, retake Archaeopolis and …

…rout the Persian general Nachoragan in his abortive attack on Phasis.

In the autumn and winter of the same year, the imperial forces suppress a rebellion staged by the mountain tribe of the Misimians, and finally expel the Persians from Lazica.