king had decided concerning the interests of the Lazi.  But Pharsanses secretly revealed to Goubazes what was being prepared.  He, accordingly, did not come to Phabrizus at all, but began openly to plan a revolt.  Then Phabrizus commanded the other Persians to attend as carefully as they could to the guarding of Petra, and to make everything as secure as possible against a siege, and he himself with the three hundred returned homeward without having accomplished his purpose.  And Goubazes reported to the Emperor Justinian the condition in which they were, and begged him to grant forgiveness for what the Lazi had done in the past, and to come to their defence with all his strength, since they desired to be rid of the Median rule.  For if left by themselves the Colchians would not be able to repel the power of the Persians.

[549 A.D.] When the Emperor Justinian heard this, he was overjoyed, and sent seven thousand men under the leadership of Dagisthaeus and a thousand Tzani to the assistance of the Lazi.  And when this force reached the land of Colchis, they encamped together with Goubazes and the Lazi about the fortifications of Petra and commenced a siege.  But since the Persians who were there made a most stalwart defence from the wall, it came about that much time was spent in the siege; for the Persians had put away an ample store of victuals in the town.  And Chosroes, being greatly disturbed by these things, dispatched a great army of horse and foot against the besiegers, putting Mermeroes in command of them.  And when Goubazes learned of this, he considered the matter together with Dagisthaeus and acted in the manner which I shall presently set forth.

The river Boas rises close to the territory of the Tzani among the Armenians who dwell around Pharangium.  And at first its course inclines to the right for a great distance, and its stream is small and can be forded by anyone with no trouble as far as the place where the territory of the Iberians lies on the right, and the end of the Caucasus lies directly opposite.  In that place many nations have their homes, and among them the Alani and Abasgi, who are Christians and friends of the Romans from of old; also the Zechi, and after them the Huns who bear the name Sabeiri.  But when this river reaches the point which marks the termination of the Caucasus and of Iberia as well, there other waters also are added to it and it becomes much larger and from there flows on bearing the name of Phasis instead of Boas[26]; and it becomes a navigable stream as far as the so-called Euxine Sea into which it empties; and on either side of it lies Lazica.  Now on the right of the stream particularly the whole country for a great distance is populated by the people of Lazica as far as the boundary of Iberia.  For all the villages of the Lazi are here beyond the river, and towns have been built there from of old, among which are Archaeopolis, a very strong place, and Sebastopolis, and the fortress of Pitius, and Scanda and Sarapanis