Siege of Phasis The Siege of Phasis took place in 555 – 556 during the Lazic War between the Byzantine Empire and Sassanid Persia . The Persians besieged the town of Phasis in Lazica , held by the Byzantines , but failed to take it . The main source for the siege is the 6th - century historian Agathias . Background . The Lazic War had started in 541 with the defection of the Lazi under their king Gubazes II from Byzantium to Persia . The Persians quickly overran the country , but after Gubazes learned that the Persians planned to kill him , deport his people and bring in Persian colonists , he asked the Byzantines for help . In 554 , the Persians won a major victory against the Laz - Byzantine forces at Telephis , forcing the latter to withdraw to the western parts of the country , and in the next year they were able to thwart a Byzantine attack on the fortress of Onoguris . In the spring of 556 , the Persian general Nachoragan took the initiative in besieging their major stronghold , the town of Phasis , which lay at the mouth of the namesake river . Opposing forces and preparations for the siege . Nachoragan led an army of ca . 60 , 000 men . The Byzantine forces of the area were led by the " magister militum per Armeniam " Martin and his second - in - command Justin , son of Germanus . Their combined forces were less than 20 , 000 men . Nachoragan could expect an easy victory as the town and its fortifications were built of wood and were vulnerable to fire . The town ' s location between the Black Sea and the River Phasis secured it from the east , north and west . At its south side , a moat was its first line of defense . Nachoragan ' s forces however emptied the moat after days of hard work , and managed to surround the town from its river side too by building a bridge of boats across the Phasis . Meanwhile , the Byzantines had organized the defense of the city , with their forces taking their places at the various sides of the fortifications . The extreme western side , the one closest to the river , was guarded by Justin , while Martin positioned himself in the south - western side . The south side was defended by Angilas , Theodore and Philomathius . Angilas is recorded leading a regiment of Moorish peltast s and spearmen , probably meaning they were only armed with shield and lance s . Theodore led heavy infantry consisting of Tzani , a recently Christianized tribe living in the mountains above Trapezus , while Philomathius led Isauria n slingers and dart - throwers . The south - eastern side was guarded by Gibrus , who led a combined force of Heruli and Lombards . The extreme eastern side was guarded by Valerian , leading forces from the praetorian prefecture of the East . Their composition is not recorded . Finally , the Byzantine ships were placed under the protection of Dabragezas the Wend and Elmingir ( Elminegeir ) the Hun . Events of the siege . Operations started with a volley of arrows from the Persians . Martin , the overall commander of the Byzantine troops , had given instructions to the whole army to stay at their respective posts . They were to disregard attempts by the Persians to induce them to sally forth from the fortifications and fight in the open . However , Angilas and Philomathius with about two hundred of their men opened a town gate , exited the town and attacked the nearest force of Sassanids whose archers were harassing the defenders . Theodore at first attempted to restrain them , but then bowed down to " majority opinion " and followed them in attacking . He was reportedly reluctant to violate orders , but unwilling to be branded a coward by the soldiers . The Byzantine force was heavily outnumbered , and Agathias reports that they " would almost certainly have been annihilated " , but they were saved by an error of the Dailamites . The Dailamites were a force of auxiliaries , originating in the mountains of Persia . " They fought on foot , armed each with a sword , a shield , and three javelins " . They decided against attacking the Byzantines from a distance , and instead they " calmly awaited their approach " and then easily performed an encirclement . The encircled Byzantines however began a desperate attack on the enemies positioned closer to the town walls , and the Dailamites " opened up their ranks and made way from them " instead of standing their ground . Thus Angilas and the others escaped back to the safety of the city . Martin eventually conceived a ruse of war , which would both raise the morale of his soldiers and spread fear in enemy units . He called the army in an assembly , supposedly to discuss further measures of defense . The assembly was interrupted by an unknown person , posing as a messenger from Constantinople . Martin reported the contents of the " imperial message " to all those assembled . The fabricated message congratulated the defenders for their valour and informed them that reinforcements were approaching , and the " messenger " claimed that they were camped near the river Neocnus , at a short distance from the town itself . Martin then feigned indignation that newcomers would share the glory and spoil " with those who had borne the burden and the heat " , to which his troops shouted their approval , being motivated to action . The Byzantine reinforcements did not in fact exist , but news of their approach reached Nachoragan , who reacted in two ways . He first assigned a large reconnaissance force , sending them out to locate and observe the Byzantine reinforcements , and then launched the rest of his forces in a general attack on the walls , hoping to capture the city before the reinforcements arrived . He boasted that he would burn the city and its inhabitants down , and sent his camp servants to the nearby woods and instructed them to gather timber to burn down the city . He also instructed them to watch for great smoke rising to the heavens , for it would mean that the city had fallen and that they should immediately return to help . While Nachoragan was forming his plan , Justin decided to take advantage of the calm before the storm : he exited the city , leading a force of 5 , 000 men cavalrymen and an infantry brigade to " a church of great sanctity in the vicinity " . The Persians somehow failed to notice their departure , and began their great attack that same morning . Arrows and darts filled the air , while Sassanid siege weapons were attempting to destroy the wooden walls . The defenders answered by throwing " huge blocks of stone " at the weapons and smaller stones at the enemy soldiers . The initial stages of the fight lasted long enough for Justin to return from his pilgrimage . He could not return to the city , but was able to organize his own forces and attack the rear of the enemy force . Their sudden attack spread havoc , breaking through enemy lines . At least some of the Sassanid forces believed that Justin ' s men were the rumoured Byzantine reinforcements . Panicked Sassanid troops started to retreat , and most of the Dailamites left their positions to " relieve those who were being hard pressed " . Angilas and Theodore noticed that there were few troops left besieging their section of the fortifications and led a sortie against the besiegers . The few Dailamites left behind were either slain or forced to flee , " pressed in relentless pursuit " by the Byzantine force . The other Dailamites noted that their kinsmen were in peril and abandoned their current positions in an attempt to face Angilas and Theodore , but their counterattack was disorganized and ineffective . The nearby Persian forces in turn thought that the Dailamites were retreating in haste , panicked and started fleeing " ignominiously in all directions " . The Dailamites were left unsupported and " rushed to join them in flight " . Agathias regards them as the cause and victims of a " double misunderstanding " . Angilas and Theodore thus succeeded in causing a general flight of the Sassanid forces . The rest of the Byzantine troops sallied forth from behind the walls and started pursuing the fleeing enemies . The entire left wing of the Sassanid army fell apart , although the right wing remained unbroken and continued to fight . The right wing included the war elephant s of the Sassanid force . They might have stopped the Byzantine advance , but one of the elephants panicked and turned against the Persian ranks . The horses of the Sassanid cavalry were terrified of the attacking elephant , panicked in turn and bolted . In the confusion , the Sassanid forces scattered . Nachoragan gave the command to retreat , but by that time most of his forces had either already fled the battlefield or were in the process of doing so . By the time night fell , the Persians had reportedly lost at least ten thousand fighting men and most of their siege equipment . The Byzantine casualties " did not number more than two hundred " . The Byzantines set the siege equipment on fire . The servants and porters of the Sassanid army reportedly mistook the smoke for a sign that the city had fallen , and started rushing towards the Byzantine lines . Nearly two thousand of them were killed that night , others captured . Aftermath . Nachoragan was already running out of supplies and winter was approaching . He broke off the siege and retreated the following day . His troops headed towards Kotais and Mochereisis . Sassanid reinforcements arrived too late to make a difference and also retreated . The Byzantine forces were left in undisputed control of the western districts of Lazica . Nachoragan eventually crossed into Caucasian Iberia to winter . News of the disaster however reached the Persian shah , Khosrau I ( r . 531 – 579 ) , who was enraged with his general . Agathias reports that Nachoragan was flayed alive by orders of Khosrau . " His skin , torn off in one piece from head to foot , so as to retain the shape of the body , was sewn up and inflated like a bladder " . Khosrau reportedly kept it on display as a warning against " anyone who fled before the enemies " of the King of Kings .